diff --git a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
index 5fd9ecf451366..fd78b483b75f2 100644
--- a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
@@ -4,6 +4,7 @@ use rustc_errors::{Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed
 use rustc_infer::infer::{
     error_reporting::nice_region_error::NiceRegionError,
     error_reporting::unexpected_hidden_region_diagnostic, NllRegionVariableOrigin,
+    RelateParamBound,
 };
 use rustc_middle::hir::place::PlaceBase;
 use rustc_middle::mir::{ConstraintCategory, ReturnConstraint};
@@ -166,11 +167,14 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                     let type_test_span = type_test.locations.span(&self.body);
 
                     if let Some(lower_bound_region) = lower_bound_region {
+                        let generic_ty = type_test.generic_kind.to_ty(self.infcx.tcx);
+                        let origin = RelateParamBound(type_test_span, generic_ty, None);
                         self.buffer_error(self.infcx.construct_generic_bound_failure(
                             type_test_span,
-                            None,
+                            Some(origin),
                             type_test.generic_kind,
                             lower_bound_region,
+                            self.body.source.def_id().as_local(),
                         ));
                     } else {
                         // FIXME. We should handle this case better. It
diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
index f2dd4f5d5cbca..f9273cc50b70a 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
@@ -61,7 +61,7 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_errors::{pluralize, struct_span_err, Diagnostic, ErrorGuaranteed};
 use rustc_errors::{Applicability, DiagnosticBuilder, DiagnosticStyledString, MultiSpan};
 use rustc_hir as hir;
-use rustc_hir::def_id::DefId;
+use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{Item, ItemKind, Node};
 use rustc_middle::dep_graph::DepContext;
@@ -2285,7 +2285,9 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         bound_kind: GenericKind<'tcx>,
         sub: Region<'tcx>,
     ) {
-        self.construct_generic_bound_failure(span, origin, bound_kind, sub).emit();
+        let owner =
+            self.in_progress_typeck_results.map(|typeck_results| typeck_results.borrow().hir_owner);
+        self.construct_generic_bound_failure(span, origin, bound_kind, sub, owner).emit();
     }
 
     pub fn construct_generic_bound_failure(
@@ -2294,31 +2296,29 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         origin: Option<SubregionOrigin<'tcx>>,
         bound_kind: GenericKind<'tcx>,
         sub: Region<'tcx>,
+        owner: Option<LocalDefId>,
     ) -> DiagnosticBuilder<'a, ErrorGuaranteed> {
         let hir = self.tcx.hir();
         // Attempt to obtain the span of the parameter so we can
         // suggest adding an explicit lifetime bound to it.
-        let generics = self
-            .in_progress_typeck_results
-            .map(|typeck_results| typeck_results.borrow().hir_owner)
-            .map(|owner| {
-                let hir_id = hir.local_def_id_to_hir_id(owner);
-                let parent_id = hir.get_parent_item(hir_id);
-                (
-                    // Parent item could be a `mod`, so we check the HIR before calling:
-                    if let Some(Node::Item(Item {
-                        kind: ItemKind::Trait(..) | ItemKind::Impl { .. },
-                        ..
-                    })) = hir.find_by_def_id(parent_id)
-                    {
-                        Some(self.tcx.generics_of(parent_id))
-                    } else {
-                        None
-                    },
-                    self.tcx.generics_of(owner.to_def_id()),
-                    hir.span(hir_id),
-                )
-            });
+        let generics = owner.map(|owner| {
+            let hir_id = hir.local_def_id_to_hir_id(owner);
+            let parent_id = hir.get_parent_item(hir_id);
+            (
+                // Parent item could be a `mod`, so we check the HIR before calling:
+                if let Some(Node::Item(Item {
+                    kind: ItemKind::Trait(..) | ItemKind::Impl { .. },
+                    ..
+                })) = hir.find_by_def_id(parent_id)
+                {
+                    Some(self.tcx.generics_of(parent_id))
+                } else {
+                    None
+                },
+                self.tcx.generics_of(owner.to_def_id()),
+                hir.span(hir_id),
+            )
+        });
 
         let span = match generics {
             // This is to get around the trait identity obligation, that has a `DUMMY_SP` as signal
@@ -2606,11 +2606,8 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                     None,
                 );
                 if let Some(infer::RelateParamBound(_, t, _)) = origin {
-                    let return_impl_trait = self
-                        .in_progress_typeck_results
-                        .map(|typeck_results| typeck_results.borrow().hir_owner)
-                        .and_then(|owner| self.tcx.return_type_impl_trait(owner))
-                        .is_some();
+                    let return_impl_trait =
+                        owner.and_then(|owner| self.tcx.return_type_impl_trait(owner)).is_some();
                     let t = self.resolve_vars_if_possible(t);
                     match t.kind() {
                         // We've got:
diff --git a/src/bootstrap/builder/tests.rs b/src/bootstrap/builder/tests.rs
index a59f72ed968b4..3b6cd7564f08a 100644
--- a/src/bootstrap/builder/tests.rs
+++ b/src/bootstrap/builder/tests.rs
@@ -7,6 +7,7 @@ fn configure(cmd: &str, host: &[&str], target: &[&str]) -> Config {
     // don't save toolstates
     config.save_toolstates = None;
     config.dry_run = true;
+    config.submodules = Some(false);
     config.ninja_in_file = false;
     // try to avoid spurious failures in dist where we create/delete each others file
     // HACK: rather than pull in `tempdir`, use the one that cargo has conveniently created for us
@@ -25,36 +26,74 @@ fn first<A, B>(v: Vec<(A, B)>) -> Vec<A> {
     v.into_iter().map(|(a, _)| a).collect::<Vec<_>>()
 }
 
+fn run_build(paths: &[PathBuf], config: Config) -> Cache {
+    let kind = config.cmd.kind();
+    let build = Build::new(config);
+    let builder = Builder::new(&build);
+    builder.run_step_descriptions(&Builder::get_step_descriptions(kind), paths);
+    builder.cache
+}
+
+#[test]
+fn test_exclude() {
+    let mut config = configure("test", &["A"], &["A"]);
+    config.exclude = vec![TaskPath::parse("src/tools/tidy")];
+    let cache = run_build(&[], config);
+
+    // Ensure we have really excluded tidy
+    assert!(!cache.contains::<test::Tidy>());
+
+    // Ensure other tests are not affected.
+    assert!(cache.contains::<test::RustdocUi>());
+}
+
+#[test]
+fn test_exclude_kind() {
+    let path = PathBuf::from("src/tools/cargotest");
+    let exclude = TaskPath::parse("test::src/tools/cargotest");
+    assert_eq!(exclude, TaskPath { kind: Some(Kind::Test), path: path.clone() });
+
+    let mut config = configure("test", &["A"], &["A"]);
+    // Ensure our test is valid, and `test::Cargotest` would be run without the exclude.
+    assert!(run_build(&[path.clone()], config.clone()).contains::<test::Cargotest>());
+    // Ensure tests for cargotest are skipped.
+    config.exclude = vec![exclude.clone()];
+    assert!(!run_build(&[path.clone()], config).contains::<test::Cargotest>());
+
+    // Ensure builds for cargotest are not skipped.
+    let mut config = configure("build", &["A"], &["A"]);
+    config.exclude = vec![exclude];
+    assert!(run_build(&[path], config).contains::<tool::CargoTest>());
+}
+
 mod defaults {
-    use super::{configure, first};
+    use super::{configure, first, run_build};
     use crate::builder::*;
     use crate::Config;
     use pretty_assertions::assert_eq;
 
     #[test]
     fn build_default() {
-        let build = Build::new(configure("build", &["A"], &["A"]));
-        let mut builder = Builder::new(&build);
-        builder.run_step_descriptions(&Builder::get_step_descriptions(Kind::Build), &[]);
+        let mut cache = run_build(&[], configure("build", &["A"], &["A"]));
 
         let a = TargetSelection::from_user("A");
         assert_eq!(
-            first(builder.cache.all::<compile::Std>()),
+            first(cache.all::<compile::Std>()),
             &[
                 compile::Std { compiler: Compiler { host: a, stage: 0 }, target: a },
                 compile::Std { compiler: Compiler { host: a, stage: 1 }, target: a },
             ]
         );
-        assert!(!builder.cache.all::<compile::Assemble>().is_empty());
+        assert!(!cache.all::<compile::Assemble>().is_empty());
         // Make sure rustdoc is only built once.
         assert_eq!(
-            first(builder.cache.all::<tool::Rustdoc>()),
+            first(cache.all::<tool::Rustdoc>()),
             // Recall that rustdoc stages are off-by-one
             // - this is the compiler it's _linked_ to, not built with.
             &[tool::Rustdoc { compiler: Compiler { host: a, stage: 1 } }],
         );
         assert_eq!(
-            first(builder.cache.all::<compile::Rustc>()),
+            first(cache.all::<compile::Rustc>()),
             &[compile::Rustc { compiler: Compiler { host: a, stage: 0 }, target: a },]
         );
     }
@@ -62,31 +101,27 @@ mod defaults {
     #[test]
     fn build_stage_0() {
         let config = Config { stage: 0, ..configure("build", &["A"], &["A"]) };
-        let build = Build::new(config);
-        let mut builder = Builder::new(&build);
-        builder.run_step_descriptions(&Builder::get_step_descriptions(Kind::Build), &[]);
+        let mut cache = run_build(&[], config);
 
         let a = TargetSelection::from_user("A");
         assert_eq!(
-            first(builder.cache.all::<compile::Std>()),
+            first(cache.all::<compile::Std>()),
             &[compile::Std { compiler: Compiler { host: a, stage: 0 }, target: a },]
         );
-        assert!(!builder.cache.all::<compile::Assemble>().is_empty());
+        assert!(!cache.all::<compile::Assemble>().is_empty());
         assert_eq!(
-            first(builder.cache.all::<tool::Rustdoc>()),
+            first(cache.all::<tool::Rustdoc>()),
             // This is the beta rustdoc.
             // Add an assert here to make sure this is the only rustdoc built.
             &[tool::Rustdoc { compiler: Compiler { host: a, stage: 0 } }],
         );
-        assert!(builder.cache.all::<compile::Rustc>().is_empty());
+        assert!(cache.all::<compile::Rustc>().is_empty());
     }
 
     #[test]
     fn build_cross_compile() {
         let config = Config { stage: 1, ..configure("build", &["A", "B"], &["A", "B"]) };
-        let build = Build::new(config);
-        let mut builder = Builder::new(&build);
-        builder.run_step_descriptions(&Builder::get_step_descriptions(Kind::Build), &[]);
+        let mut cache = run_build(&[], config);
 
         let a = TargetSelection::from_user("A");
         let b = TargetSelection::from_user("B");
@@ -97,7 +132,7 @@ mod defaults {
         // (since we're producing stage 1 libraries/binaries).  But currently
         // rustbuild is just a bit buggy here; this should be fixed though.
         assert_eq!(
-            first(builder.cache.all::<compile::Std>()),
+            first(cache.all::<compile::Std>()),
             &[
                 compile::Std { compiler: Compiler { host: a, stage: 0 }, target: a },
                 compile::Std { compiler: Compiler { host: a, stage: 1 }, target: a },
@@ -106,7 +141,7 @@ mod defaults {
             ]
         );
         assert_eq!(
-            first(builder.cache.all::<compile::Assemble>()),
+            first(cache.all::<compile::Assemble>()),
             &[
                 compile::Assemble { target_compiler: Compiler { host: a, stage: 0 } },
                 compile::Assemble { target_compiler: Compiler { host: a, stage: 1 } },
@@ -114,14 +149,14 @@ mod defaults {
             ]
         );
         assert_eq!(
-            first(builder.cache.all::<tool::Rustdoc>()),
+            first(cache.all::<tool::Rustdoc>()),
             &[
                 tool::Rustdoc { compiler: Compiler { host: a, stage: 1 } },
                 tool::Rustdoc { compiler: Compiler { host: b, stage: 1 } },
             ],
         );
         assert_eq!(
-            first(builder.cache.all::<compile::Rustc>()),
+            first(cache.all::<compile::Rustc>()),
             &[
                 compile::Rustc { compiler: Compiler { host: a, stage: 0 }, target: a },
                 compile::Rustc { compiler: Compiler { host: a, stage: 0 }, target: b },
@@ -134,33 +169,28 @@ mod defaults {
         let mut config = configure("doc", &["A"], &["A"]);
         config.compiler_docs = true;
         config.cmd = Subcommand::Doc { paths: Vec::new(), open: false };
-        let build = Build::new(config);
-        let mut builder = Builder::new(&build);
-        builder.run_step_descriptions(&Builder::get_step_descriptions(Kind::Doc), &[]);
+        let mut cache = run_build(&[], config);
         let a = TargetSelection::from_user("A");
 
         // error_index_generator uses stage 0 to share rustdoc artifacts with the
         // rustdoc tool.
+        assert_eq!(first(cache.all::<doc::ErrorIndex>()), &[doc::ErrorIndex { target: a },]);
         assert_eq!(
-            first(builder.cache.all::<doc::ErrorIndex>()),
-            &[doc::ErrorIndex { target: a },]
-        );
-        assert_eq!(
-            first(builder.cache.all::<tool::ErrorIndex>()),
+            first(cache.all::<tool::ErrorIndex>()),
             &[tool::ErrorIndex { compiler: Compiler { host: a, stage: 0 } }]
         );
         // docs should be built with the beta compiler, not with the stage0 artifacts.
         // recall that rustdoc is off-by-one: `stage` is the compiler rustdoc is _linked_ to,
         // not the one it was built by.
         assert_eq!(
-            first(builder.cache.all::<tool::Rustdoc>()),
+            first(cache.all::<tool::Rustdoc>()),
             &[tool::Rustdoc { compiler: Compiler { host: a, stage: 0 } },]
         );
     }
 }
 
 mod dist {
-    use super::{first, Config};
+    use super::{first, run_build, Config};
     use crate::builder::*;
     use pretty_assertions::assert_eq;
 
@@ -170,94 +200,88 @@ mod dist {
 
     #[test]
     fn dist_baseline() {
-        let build = Build::new(configure(&["A"], &["A"]));
-        let mut builder = Builder::new(&build);
-        builder.run_step_descriptions(&Builder::get_step_descriptions(Kind::Dist), &[]);
+        let mut cache = run_build(&[], configure(&["A"], &["A"]));
 
         let a = TargetSelection::from_user("A");
 
-        assert_eq!(first(builder.cache.all::<dist::Docs>()), &[dist::Docs { host: a },]);
-        assert_eq!(first(builder.cache.all::<dist::Mingw>()), &[dist::Mingw { host: a },]);
+        assert_eq!(first(cache.all::<dist::Docs>()), &[dist::Docs { host: a },]);
+        assert_eq!(first(cache.all::<dist::Mingw>()), &[dist::Mingw { host: a },]);
         assert_eq!(
-            first(builder.cache.all::<dist::Rustc>()),
+            first(cache.all::<dist::Rustc>()),
             &[dist::Rustc { compiler: Compiler { host: a, stage: 2 } },]
         );
         assert_eq!(
-            first(builder.cache.all::<dist::Std>()),
+            first(cache.all::<dist::Std>()),
             &[dist::Std { compiler: Compiler { host: a, stage: 1 }, target: a },]
         );
-        assert_eq!(first(builder.cache.all::<dist::Src>()), &[dist::Src]);
+        assert_eq!(first(cache.all::<dist::Src>()), &[dist::Src]);
         // Make sure rustdoc is only built once.
         assert_eq!(
-            first(builder.cache.all::<tool::Rustdoc>()),
+            first(cache.all::<tool::Rustdoc>()),
             &[tool::Rustdoc { compiler: Compiler { host: a, stage: 2 } },]
         );
     }
 
     #[test]
     fn dist_with_targets() {
-        let build = Build::new(configure(&["A"], &["A", "B"]));
-        let mut builder = Builder::new(&build);
-        builder.run_step_descriptions(&Builder::get_step_descriptions(Kind::Dist), &[]);
+        let mut cache = run_build(&[], configure(&["A"], &["A", "B"]));
 
         let a = TargetSelection::from_user("A");
         let b = TargetSelection::from_user("B");
 
         assert_eq!(
-            first(builder.cache.all::<dist::Docs>()),
+            first(cache.all::<dist::Docs>()),
             &[dist::Docs { host: a }, dist::Docs { host: b },]
         );
         assert_eq!(
-            first(builder.cache.all::<dist::Mingw>()),
+            first(cache.all::<dist::Mingw>()),
             &[dist::Mingw { host: a }, dist::Mingw { host: b },]
         );
         assert_eq!(
-            first(builder.cache.all::<dist::Rustc>()),
+            first(cache.all::<dist::Rustc>()),
             &[dist::Rustc { compiler: Compiler { host: a, stage: 2 } },]
         );
         assert_eq!(
-            first(builder.cache.all::<dist::Std>()),
+            first(cache.all::<dist::Std>()),
             &[
                 dist::Std { compiler: Compiler { host: a, stage: 1 }, target: a },
                 dist::Std { compiler: Compiler { host: a, stage: 2 }, target: b },
             ]
         );
-        assert_eq!(first(builder.cache.all::<dist::Src>()), &[dist::Src]);
+        assert_eq!(first(cache.all::<dist::Src>()), &[dist::Src]);
     }
 
     #[test]
     fn dist_with_hosts() {
-        let build = Build::new(configure(&["A", "B"], &["A", "B"]));
-        let mut builder = Builder::new(&build);
-        builder.run_step_descriptions(&Builder::get_step_descriptions(Kind::Dist), &[]);
+        let mut cache = run_build(&[], configure(&["A", "B"], &["A", "B"]));
 
         let a = TargetSelection::from_user("A");
         let b = TargetSelection::from_user("B");
 
         assert_eq!(
-            first(builder.cache.all::<dist::Docs>()),
+            first(cache.all::<dist::Docs>()),
             &[dist::Docs { host: a }, dist::Docs { host: b },]
         );
         assert_eq!(
-            first(builder.cache.all::<dist::Mingw>()),
+            first(cache.all::<dist::Mingw>()),
             &[dist::Mingw { host: a }, dist::Mingw { host: b },]
         );
         assert_eq!(
-            first(builder.cache.all::<dist::Rustc>()),
+            first(cache.all::<dist::Rustc>()),
             &[
                 dist::Rustc { compiler: Compiler { host: a, stage: 2 } },
                 dist::Rustc { compiler: Compiler { host: b, stage: 2 } },
             ]
         );
         assert_eq!(
-            first(builder.cache.all::<dist::Std>()),
+            first(cache.all::<dist::Std>()),
             &[
                 dist::Std { compiler: Compiler { host: a, stage: 1 }, target: a },
                 dist::Std { compiler: Compiler { host: a, stage: 1 }, target: b },
             ]
         );
         assert_eq!(
-            first(builder.cache.all::<compile::Std>()),
+            first(cache.all::<compile::Std>()),
             &[
                 compile::Std { compiler: Compiler { host: a, stage: 0 }, target: a },
                 compile::Std { compiler: Compiler { host: a, stage: 1 }, target: a },
@@ -266,26 +290,25 @@ mod dist {
                 compile::Std { compiler: Compiler { host: a, stage: 2 }, target: b },
             ],
         );
-        assert_eq!(first(builder.cache.all::<dist::Src>()), &[dist::Src]);
+        assert_eq!(first(cache.all::<dist::Src>()), &[dist::Src]);
     }
 
     #[test]
     fn dist_only_cross_host() {
         let a = TargetSelection::from_user("A");
         let b = TargetSelection::from_user("B");
-        let mut build = Build::new(configure(&["A", "B"], &["A", "B"]));
-        build.config.docs = false;
-        build.config.extended = true;
-        build.hosts = vec![b];
-        let mut builder = Builder::new(&build);
-        builder.run_step_descriptions(&Builder::get_step_descriptions(Kind::Dist), &[]);
+        let mut config = configure(&["A", "B"], &["A", "B"]);
+        config.docs = false;
+        config.extended = true;
+        config.hosts = vec![b];
+        let mut cache = run_build(&[], config);
 
         assert_eq!(
-            first(builder.cache.all::<dist::Rustc>()),
+            first(cache.all::<dist::Rustc>()),
             &[dist::Rustc { compiler: Compiler { host: b, stage: 2 } },]
         );
         assert_eq!(
-            first(builder.cache.all::<compile::Rustc>()),
+            first(cache.all::<compile::Rustc>()),
             &[
                 compile::Rustc { compiler: Compiler { host: a, stage: 0 }, target: a },
                 compile::Rustc { compiler: Compiler { host: a, stage: 1 }, target: b },
@@ -295,92 +318,86 @@ mod dist {
 
     #[test]
     fn dist_with_targets_and_hosts() {
-        let build = Build::new(configure(&["A", "B"], &["A", "B", "C"]));
-        let mut builder = Builder::new(&build);
-        builder.run_step_descriptions(&Builder::get_step_descriptions(Kind::Dist), &[]);
+        let mut cache = run_build(&[], configure(&["A", "B"], &["A", "B", "C"]));
 
         let a = TargetSelection::from_user("A");
         let b = TargetSelection::from_user("B");
         let c = TargetSelection::from_user("C");
 
         assert_eq!(
-            first(builder.cache.all::<dist::Docs>()),
+            first(cache.all::<dist::Docs>()),
             &[dist::Docs { host: a }, dist::Docs { host: b }, dist::Docs { host: c },]
         );
         assert_eq!(
-            first(builder.cache.all::<dist::Mingw>()),
+            first(cache.all::<dist::Mingw>()),
             &[dist::Mingw { host: a }, dist::Mingw { host: b }, dist::Mingw { host: c },]
         );
         assert_eq!(
-            first(builder.cache.all::<dist::Rustc>()),
+            first(cache.all::<dist::Rustc>()),
             &[
                 dist::Rustc { compiler: Compiler { host: a, stage: 2 } },
                 dist::Rustc { compiler: Compiler { host: b, stage: 2 } },
             ]
         );
         assert_eq!(
-            first(builder.cache.all::<dist::Std>()),
+            first(cache.all::<dist::Std>()),
             &[
                 dist::Std { compiler: Compiler { host: a, stage: 1 }, target: a },
                 dist::Std { compiler: Compiler { host: a, stage: 1 }, target: b },
                 dist::Std { compiler: Compiler { host: a, stage: 2 }, target: c },
             ]
         );
-        assert_eq!(first(builder.cache.all::<dist::Src>()), &[dist::Src]);
+        assert_eq!(first(cache.all::<dist::Src>()), &[dist::Src]);
     }
 
     #[test]
     fn dist_with_empty_host() {
         let config = configure(&[], &["C"]);
-        let build = Build::new(config);
-        let mut builder = Builder::new(&build);
-        builder.run_step_descriptions(&Builder::get_step_descriptions(Kind::Dist), &[]);
+        let mut cache = run_build(&[], config);
 
         let a = TargetSelection::from_user("A");
         let c = TargetSelection::from_user("C");
 
-        assert_eq!(first(builder.cache.all::<dist::Docs>()), &[dist::Docs { host: c },]);
-        assert_eq!(first(builder.cache.all::<dist::Mingw>()), &[dist::Mingw { host: c },]);
+        assert_eq!(first(cache.all::<dist::Docs>()), &[dist::Docs { host: c },]);
+        assert_eq!(first(cache.all::<dist::Mingw>()), &[dist::Mingw { host: c },]);
         assert_eq!(
-            first(builder.cache.all::<dist::Std>()),
+            first(cache.all::<dist::Std>()),
             &[dist::Std { compiler: Compiler { host: a, stage: 2 }, target: c },]
         );
     }
 
     #[test]
     fn dist_with_same_targets_and_hosts() {
-        let build = Build::new(configure(&["A", "B"], &["A", "B"]));
-        let mut builder = Builder::new(&build);
-        builder.run_step_descriptions(&Builder::get_step_descriptions(Kind::Dist), &[]);
+        let mut cache = run_build(&[], configure(&["A", "B"], &["A", "B"]));
 
         let a = TargetSelection::from_user("A");
         let b = TargetSelection::from_user("B");
 
         assert_eq!(
-            first(builder.cache.all::<dist::Docs>()),
+            first(cache.all::<dist::Docs>()),
             &[dist::Docs { host: a }, dist::Docs { host: b },]
         );
         assert_eq!(
-            first(builder.cache.all::<dist::Mingw>()),
+            first(cache.all::<dist::Mingw>()),
             &[dist::Mingw { host: a }, dist::Mingw { host: b },]
         );
         assert_eq!(
-            first(builder.cache.all::<dist::Rustc>()),
+            first(cache.all::<dist::Rustc>()),
             &[
                 dist::Rustc { compiler: Compiler { host: a, stage: 2 } },
                 dist::Rustc { compiler: Compiler { host: b, stage: 2 } },
             ]
         );
         assert_eq!(
-            first(builder.cache.all::<dist::Std>()),
+            first(cache.all::<dist::Std>()),
             &[
                 dist::Std { compiler: Compiler { host: a, stage: 1 }, target: a },
                 dist::Std { compiler: Compiler { host: a, stage: 1 }, target: b },
             ]
         );
-        assert_eq!(first(builder.cache.all::<dist::Src>()), &[dist::Src]);
+        assert_eq!(first(cache.all::<dist::Src>()), &[dist::Src]);
         assert_eq!(
-            first(builder.cache.all::<compile::Std>()),
+            first(cache.all::<compile::Std>()),
             &[
                 compile::Std { compiler: Compiler { host: a, stage: 0 }, target: a },
                 compile::Std { compiler: Compiler { host: a, stage: 1 }, target: a },
@@ -390,7 +407,7 @@ mod dist {
             ]
         );
         assert_eq!(
-            first(builder.cache.all::<compile::Assemble>()),
+            first(cache.all::<compile::Assemble>()),
             &[
                 compile::Assemble { target_compiler: Compiler { host: a, stage: 0 } },
                 compile::Assemble { target_compiler: Compiler { host: a, stage: 1 } },
@@ -514,35 +531,6 @@ mod dist {
         );
     }
 
-    #[test]
-    fn test_exclude() {
-        let mut config = configure(&["A"], &["A"]);
-        config.exclude = vec![TaskPath::parse("src/tools/tidy")];
-        config.cmd = Subcommand::Test {
-            paths: Vec::new(),
-            test_args: Vec::new(),
-            rustc_args: Vec::new(),
-            fail_fast: true,
-            doc_tests: DocTests::No,
-            bless: false,
-            force_rerun: false,
-            compare_mode: None,
-            rustfix_coverage: false,
-            pass: None,
-            run: None,
-        };
-
-        let build = Build::new(config);
-        let builder = Builder::new(&build);
-        builder.run_step_descriptions(&Builder::get_step_descriptions(Kind::Test), &[]);
-
-        // Ensure we have really excluded tidy
-        assert!(!builder.cache.contains::<test::Tidy>());
-
-        // Ensure other tests are not affected.
-        assert!(builder.cache.contains::<test::RustdocUi>());
-    }
-
     #[test]
     fn doc_ci() {
         let mut config = configure(&["A"], &["A"]);
diff --git a/src/bootstrap/check.rs b/src/bootstrap/check.rs
index 432a6c34ed584..731ebc41bb9a0 100644
--- a/src/bootstrap/check.rs
+++ b/src/bootstrap/check.rs
@@ -64,7 +64,7 @@ impl Step for Std {
     const DEFAULT: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.all_krates("test")
+        run.all_krates("test").path("library")
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -162,7 +162,7 @@ impl Step for Rustc {
     const DEFAULT: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.all_krates("rustc-main")
+        run.all_krates("rustc-main").path("compiler")
     }
 
     fn make_run(run: RunConfig<'_>) {
diff --git a/src/bootstrap/compile.rs b/src/bootstrap/compile.rs
index 45991381dc0fe..a212c659b5c2b 100644
--- a/src/bootstrap/compile.rs
+++ b/src/bootstrap/compile.rs
@@ -43,7 +43,7 @@ impl Step for Std {
         // When downloading stage1, the standard library has already been copied to the sysroot, so
         // there's no need to rebuild it.
         let download_rustc = run.builder.config.download_rustc;
-        run.all_krates("test").default_condition(!download_rustc)
+        run.all_krates("test").path("library").default_condition(!download_rustc)
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -1047,7 +1047,7 @@ impl Step for Assemble {
     const ONLY_HOSTS: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("compiler/rustc")
+        run.path("compiler/rustc").path("compiler")
     }
 
     fn make_run(run: RunConfig<'_>) {
diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs
index f273fb42215e9..1638d3ed3c281 100644
--- a/src/bootstrap/config.rs
+++ b/src/bootstrap/config.rs
@@ -41,6 +41,7 @@ macro_rules! check_ci_llvm {
 /// each field, see the corresponding fields in
 /// `config.toml.example`.
 #[derive(Default)]
+#[cfg_attr(test, derive(Clone))]
 pub struct Config {
     pub changelog_seen: Option<usize>,
     pub ccache: Option<String>,
@@ -330,6 +331,7 @@ impl PartialEq<&str> for TargetSelection {
 
 /// Per-target configuration stored in the global configuration structure.
 #[derive(Default)]
+#[cfg_attr(test, derive(Clone))]
 pub struct Target {
     /// Some(path to llvm-config) if using an external LLVM.
     pub llvm_config: Option<PathBuf>,
diff --git a/src/bootstrap/doc.rs b/src/bootstrap/doc.rs
index a2802f76008a3..fcef784d2d1fa 100644
--- a/src/bootstrap/doc.rs
+++ b/src/bootstrap/doc.rs
@@ -416,7 +416,7 @@ impl Step for Std {
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
-        run.all_krates("test").default_condition(builder.config.docs)
+        run.all_krates("test").path("library").default_condition(builder.config.docs)
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -477,11 +477,14 @@ impl Step for Std {
             .iter()
             .map(components_simplified)
             .filter_map(|path| {
-                if path.get(0) == Some(&"library") {
+                if path.len() >= 2 && path.get(0) == Some(&"library") {
+                    // single crate
                     Some(path[1].to_owned())
                 } else if !path.is_empty() {
+                    // ??
                     Some(path[0].to_owned())
                 } else {
+                    // all library crates
                     None
                 }
             })
diff --git a/src/bootstrap/flags.rs b/src/bootstrap/flags.rs
index a82eb52e232b4..58571ea129c19 100644
--- a/src/bootstrap/flags.rs
+++ b/src/bootstrap/flags.rs
@@ -14,6 +14,7 @@ use crate::setup::Profile;
 use crate::util::t;
 use crate::{Build, DocTests};
 
+#[derive(Copy, Clone)]
 pub enum Color {
     Always,
     Never,
@@ -79,6 +80,7 @@ pub struct Flags {
     pub llvm_profile_generate: bool,
 }
 
+#[cfg_attr(test, derive(Clone))]
 pub enum Subcommand {
     Build {
         paths: Vec<PathBuf>,
@@ -668,6 +670,24 @@ Arguments:
 }
 
 impl Subcommand {
+    pub fn kind(&self) -> Kind {
+        match self {
+            Subcommand::Bench { .. } => Kind::Bench,
+            Subcommand::Build { .. } => Kind::Build,
+            Subcommand::Check { .. } => Kind::Check,
+            Subcommand::Clippy { .. } => Kind::Clippy,
+            Subcommand::Doc { .. } => Kind::Doc,
+            Subcommand::Fix { .. } => Kind::Fix,
+            Subcommand::Format { .. } => Kind::Format,
+            Subcommand::Test { .. } => Kind::Test,
+            Subcommand::Clean { .. } => Kind::Clean,
+            Subcommand::Dist { .. } => Kind::Dist,
+            Subcommand::Install { .. } => Kind::Install,
+            Subcommand::Run { .. } => Kind::Run,
+            Subcommand::Setup { .. } => Kind::Setup,
+        }
+    }
+
     pub fn test_args(&self) -> Vec<&str> {
         match *self {
             Subcommand::Test { ref test_args, .. } | Subcommand::Bench { ref test_args, .. } => {
diff --git a/src/bootstrap/test.rs b/src/bootstrap/test.rs
index da4689098119f..9c376602d283f 100644
--- a/src/bootstrap/test.rs
+++ b/src/bootstrap/test.rs
@@ -1400,9 +1400,7 @@ note: if you're sure you want to do this, please open an issue as to why. In the
         targetflags.extend(builder.lld_flags(target));
         cmd.arg("--target-rustcflags").arg(targetflags.join(" "));
 
-        cmd.arg("--docck-python").arg(builder.python());
-
-        cmd.arg("--lldb-python").arg(builder.python());
+        cmd.arg("--python").arg(builder.python());
 
         if let Some(ref gdb) = builder.config.gdb {
             cmd.arg("--gdb").arg(gdb);
diff --git a/src/test/ui/impl-trait/must_outlive_least_region_or_bound.nll.stderr b/src/test/ui/impl-trait/must_outlive_least_region_or_bound.nll.stderr
index 9589b69491e25..0059f729bae2f 100644
--- a/src/test/ui/impl-trait/must_outlive_least_region_or_bound.nll.stderr
+++ b/src/test/ui/impl-trait/must_outlive_least_region_or_bound.nll.stderr
@@ -82,10 +82,11 @@ LL | fn move_lifetime_into_fn<'a, 'b>(x: &'a u32, y: &'b u32) -> impl Fn(&'a u32
 error[E0310]: the parameter type `T` may not live long enough
   --> $DIR/must_outlive_least_region_or_bound.rs:41:5
    |
+LL | fn ty_param_wont_outlive_static<T:Debug>(x: T) -> impl Debug + 'static {
+   |                                 -- help: consider adding an explicit lifetime bound...: `T: 'static +`
+...
 LL |     x
-   |     ^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'static`...
+   |     ^ ...so that the type `T` will meet its required lifetime bounds
 
 error: aborting due to 9 previous errors
 
diff --git a/src/test/ui/impl-trait/type_parameters_captured.nll.stderr b/src/test/ui/impl-trait/type_parameters_captured.nll.stderr
index b1175a5952e59..5328b077993c5 100644
--- a/src/test/ui/impl-trait/type_parameters_captured.nll.stderr
+++ b/src/test/ui/impl-trait/type_parameters_captured.nll.stderr
@@ -1,10 +1,11 @@
 error[E0310]: the parameter type `T` may not live long enough
   --> $DIR/type_parameters_captured.rs:10:5
    |
+LL | fn foo<T>(x: T) -> impl Any + 'static {
+   |        - help: consider adding an explicit lifetime bound...: `T: 'static`
+...
 LL |     x
-   |     ^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'static`...
+   |     ^ ...so that the type `T` will meet its required lifetime bounds
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/lifetimes/lifetime-errors/issue_74400.nll.stderr b/src/test/ui/lifetimes/lifetime-errors/issue_74400.nll.stderr
index 5509226cb1cdd..422673b361a95 100644
--- a/src/test/ui/lifetimes/lifetime-errors/issue_74400.nll.stderr
+++ b/src/test/ui/lifetimes/lifetime-errors/issue_74400.nll.stderr
@@ -1,10 +1,10 @@
 error[E0310]: the parameter type `T` may not live long enough
   --> $DIR/issue_74400.rs:12:5
    |
+LL | fn g<T>(data: &[T]) {
+   |      - help: consider adding an explicit lifetime bound...: `T: 'static`
 LL |     f(data, identity)
-   |     ^^^^^^^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'static`...
+   |     ^^^^^^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds
 
 error[E0308]: mismatched types
   --> $DIR/issue_74400.rs:12:5
diff --git a/src/test/ui/methods/issues/issue-90315.rs b/src/test/ui/methods/issues/issue-90315.rs
new file mode 100644
index 0000000000000..01bf9f4840246
--- /dev/null
+++ b/src/test/ui/methods/issues/issue-90315.rs
@@ -0,0 +1,7 @@
+fn main() {
+  let arr = &[0,1,2,3];
+  for _i in 0..arr.len().rev() { //~ERROR not an iterator
+     // The above error used to say “the method `rev` exists for type `usize`”.
+     // This regression test ensures it doesn't say that any more.
+  }
+}
diff --git a/src/test/ui/methods/issues/issue-90315.stderr b/src/test/ui/methods/issues/issue-90315.stderr
new file mode 100644
index 0000000000000..c6a76c9e79018
--- /dev/null
+++ b/src/test/ui/methods/issues/issue-90315.stderr
@@ -0,0 +1,13 @@
+error[E0599]: `usize` is not an iterator
+  --> $DIR/issue-90315.rs:3:26
+   |
+LL |   for _i in 0..arr.len().rev() {
+   |                          ^^^ `usize` is not an iterator
+   |
+   = note: the following trait bounds were not satisfied:
+           `usize: Iterator`
+           which is required by `&mut usize: Iterator`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0599`.
diff --git a/src/test/ui/nll/closure-requirements/propagate-from-trait-match.stderr b/src/test/ui/nll/closure-requirements/propagate-from-trait-match.stderr
index 4b860a55057b6..b6856089a84f9 100644
--- a/src/test/ui/nll/closure-requirements/propagate-from-trait-match.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-from-trait-match.stderr
@@ -36,6 +36,9 @@ LL | | }
 error[E0309]: the parameter type `T` may not live long enough
   --> $DIR/propagate-from-trait-match.rs:32:36
    |
+LL |   fn supply<'a, T>(value: T)
+   |                 - help: consider adding an explicit lifetime bound...: `T: 'a`
+...
 LL |       establish_relationships(value, |value| {
    |  ____________________________________^
 LL | |
@@ -44,9 +47,7 @@ LL | |         // This function call requires that
 ...  |
 LL | |         require(value);
 LL | |     });
-   | |_____^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'a`...
+   | |_____^ ...so that the type `T` will meet its required lifetime bounds
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/nll/ty-outlives/impl-trait-outlives.stderr b/src/test/ui/nll/ty-outlives/impl-trait-outlives.stderr
index 31ee540cce9f7..3d4cfc1610a66 100644
--- a/src/test/ui/nll/ty-outlives/impl-trait-outlives.stderr
+++ b/src/test/ui/nll/ty-outlives/impl-trait-outlives.stderr
@@ -1,18 +1,20 @@
 error[E0309]: the parameter type `T` may not live long enough
   --> $DIR/impl-trait-outlives.rs:11:5
    |
+LL | fn no_region<'a, T>(x: Box<T>) -> impl Debug + 'a
+   |                  - help: consider adding an explicit lifetime bound...: `T: 'a`
+...
 LL |     x
-   |     ^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'a`...
+   |     ^ ...so that the type `T` will meet its required lifetime bounds
 
 error[E0309]: the parameter type `T` may not live long enough
   --> $DIR/impl-trait-outlives.rs:26:5
    |
+LL | fn wrong_region<'a, 'b, T>(x: Box<T>) -> impl Debug + 'a
+   |                         - help: consider adding an explicit lifetime bound...: `T: 'a`
+...
 LL |     x
-   |     ^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'a`...
+   |     ^ ...so that the type `T` will meet its required lifetime bounds
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/nll/ty-outlives/projection-implied-bounds.stderr b/src/test/ui/nll/ty-outlives/projection-implied-bounds.stderr
index 9f0c60c1e1705..cc5aa1eb11ec0 100644
--- a/src/test/ui/nll/ty-outlives/projection-implied-bounds.stderr
+++ b/src/test/ui/nll/ty-outlives/projection-implied-bounds.stderr
@@ -1,10 +1,10 @@
 error[E0310]: the parameter type `T` may not live long enough
   --> $DIR/projection-implied-bounds.rs:30:18
    |
+LL | fn generic2<T: Iterator>(value: T) {
+   |             -- help: consider adding an explicit lifetime bound...: `T: 'static +`
 LL |     twice(value, |value_ref, item| invoke2(value_ref, item));
-   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'static`...
+   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/nll/ty-outlives/projection-no-regions-closure.stderr b/src/test/ui/nll/ty-outlives/projection-no-regions-closure.stderr
index 983d6a06afada..8fe25181da1a0 100644
--- a/src/test/ui/nll/ty-outlives/projection-no-regions-closure.stderr
+++ b/src/test/ui/nll/ty-outlives/projection-no-regions-closure.stderr
@@ -33,6 +33,7 @@ LL |     with_signature(x, |mut y| Box::new(y.next()))
    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider adding an explicit lifetime bound `<T as Iterator>::Item: 'a`...
+   = note: ...so that the type `<T as Iterator>::Item` will meet its required lifetime bounds
 
 note: external requirements
   --> $DIR/projection-no-regions-closure.rs:34:23
@@ -96,6 +97,7 @@ LL |     with_signature(x, |mut y| Box::new(y.next()))
    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider adding an explicit lifetime bound `<T as Iterator>::Item: 'a`...
+   = note: ...so that the type `<T as Iterator>::Item` will meet its required lifetime bounds
 
 note: external requirements
   --> $DIR/projection-no-regions-closure.rs:52:23
diff --git a/src/test/ui/nll/ty-outlives/projection-no-regions-fn.stderr b/src/test/ui/nll/ty-outlives/projection-no-regions-fn.stderr
index c4df04b99b525..e0ff544fe4713 100644
--- a/src/test/ui/nll/ty-outlives/projection-no-regions-fn.stderr
+++ b/src/test/ui/nll/ty-outlives/projection-no-regions-fn.stderr
@@ -5,6 +5,7 @@ LL |     Box::new(x.next())
    |     ^^^^^^^^^^^^^^^^^^
    |
    = help: consider adding an explicit lifetime bound `<T as Iterator>::Item: 'a`...
+   = note: ...so that the type `<T as Iterator>::Item` will meet its required lifetime bounds
 
 error[E0309]: the associated type `<T as Iterator>::Item` may not live long enough
   --> $DIR/projection-no-regions-fn.rs:28:5
@@ -13,6 +14,7 @@ LL |     Box::new(x.next())
    |     ^^^^^^^^^^^^^^^^^^
    |
    = help: consider adding an explicit lifetime bound `<T as Iterator>::Item: 'a`...
+   = note: ...so that the type `<T as Iterator>::Item` will meet its required lifetime bounds
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/nll/ty-outlives/projection-one-region-closure.stderr b/src/test/ui/nll/ty-outlives/projection-one-region-closure.stderr
index 2513b0bfccbf1..62db6dd845a28 100644
--- a/src/test/ui/nll/ty-outlives/projection-one-region-closure.stderr
+++ b/src/test/ui/nll/ty-outlives/projection-one-region-closure.stderr
@@ -31,10 +31,11 @@ LL | | }
 error[E0309]: the parameter type `T` may not live long enough
   --> $DIR/projection-one-region-closure.rs:45:29
    |
+LL | fn no_relationships_late<'a, 'b, T>(cell: Cell<&'a ()>, t: T)
+   |                                  - help: consider adding an explicit lifetime bound...: `T: 'a`
+...
 LL |     with_signature(cell, t, |cell, t| require(cell, t));
-   |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'a`...
+   |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds
 
 error: lifetime may not live long enough
   --> $DIR/projection-one-region-closure.rs:45:39
@@ -81,10 +82,11 @@ LL | | }
 error[E0309]: the parameter type `T` may not live long enough
   --> $DIR/projection-one-region-closure.rs:56:29
    |
+LL | fn no_relationships_early<'a, 'b, T>(cell: Cell<&'a ()>, t: T)
+   |                                   - help: consider adding an explicit lifetime bound...: `T: 'a`
+...
 LL |     with_signature(cell, t, |cell, t| require(cell, t));
-   |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'a`...
+   |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds
 
 error: lifetime may not live long enough
   --> $DIR/projection-one-region-closure.rs:56:39
diff --git a/src/test/ui/nll/ty-outlives/projection-two-region-trait-bound-closure.stderr b/src/test/ui/nll/ty-outlives/projection-two-region-trait-bound-closure.stderr
index 4e0155bdf2cd0..1ee788b40ab9e 100644
--- a/src/test/ui/nll/ty-outlives/projection-two-region-trait-bound-closure.stderr
+++ b/src/test/ui/nll/ty-outlives/projection-two-region-trait-bound-closure.stderr
@@ -34,6 +34,7 @@ LL |     with_signature(cell, t, |cell, t| require(cell, t));
    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider adding an explicit lifetime bound `<T as Anything<ReEarlyBound(0, 'b), ReEarlyBound(1, 'c)>>::AssocType: 'a`...
+   = note: ...so that the type `<T as Anything<ReEarlyBound(0, 'b), ReEarlyBound(1, 'c)>>::AssocType` will meet its required lifetime bounds
 
 note: external requirements
   --> $DIR/projection-two-region-trait-bound-closure.rs:48:29
@@ -70,6 +71,7 @@ LL |     with_signature(cell, t, |cell, t| require(cell, t));
    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider adding an explicit lifetime bound `<T as Anything<ReEarlyBound(1, 'b), ReEarlyBound(2, 'c)>>::AssocType: 'a`...
+   = note: ...so that the type `<T as Anything<ReEarlyBound(1, 'b), ReEarlyBound(2, 'c)>>::AssocType` will meet its required lifetime bounds
 
 note: external requirements
   --> $DIR/projection-two-region-trait-bound-closure.rs:61:29
diff --git a/src/test/ui/nll/ty-outlives/projection-where-clause-env-wrong-bound.nll.stderr b/src/test/ui/nll/ty-outlives/projection-where-clause-env-wrong-bound.nll.stderr
index 3a84cbfbedc09..b4435fe06bccc 100644
--- a/src/test/ui/nll/ty-outlives/projection-where-clause-env-wrong-bound.nll.stderr
+++ b/src/test/ui/nll/ty-outlives/projection-where-clause-env-wrong-bound.nll.stderr
@@ -5,6 +5,7 @@ LL |     bar::<T::Output>()
    |     ^^^^^^^^^^^^^^^^
    |
    = help: consider adding an explicit lifetime bound `<T as MyTrait<'_>>::Output: 'a`...
+   = note: ...so that the type `<T as MyTrait<'_>>::Output` will meet its required lifetime bounds
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/nll/ty-outlives/projection-where-clause-env-wrong-lifetime.nll.stderr b/src/test/ui/nll/ty-outlives/projection-where-clause-env-wrong-lifetime.nll.stderr
index 58bfb600452e0..ddeaf3c1f9e8c 100644
--- a/src/test/ui/nll/ty-outlives/projection-where-clause-env-wrong-lifetime.nll.stderr
+++ b/src/test/ui/nll/ty-outlives/projection-where-clause-env-wrong-lifetime.nll.stderr
@@ -5,6 +5,7 @@ LL |     bar::<<T as MyTrait<'a>>::Output>()
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider adding an explicit lifetime bound `<T as MyTrait<'_>>::Output: 'a`...
+   = note: ...so that the type `<T as MyTrait<'_>>::Output` will meet its required lifetime bounds
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/nll/ty-outlives/projection-where-clause-none.stderr b/src/test/ui/nll/ty-outlives/projection-where-clause-none.stderr
index 8175c302155a5..c51edb7868d7a 100644
--- a/src/test/ui/nll/ty-outlives/projection-where-clause-none.stderr
+++ b/src/test/ui/nll/ty-outlives/projection-where-clause-none.stderr
@@ -1,10 +1,11 @@
 error[E0309]: the parameter type `T` may not live long enough
   --> $DIR/projection-where-clause-none.rs:16:5
    |
+LL | fn foo<'a, T>() -> &'a ()
+   |            - help: consider adding an explicit lifetime bound...: `T: 'a`
+...
 LL |     bar::<T::Output>()
-   |     ^^^^^^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'a`...
+   |     ^^^^^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/nll/ty-outlives/ty-param-closure-approximate-lower-bound.stderr b/src/test/ui/nll/ty-outlives/ty-param-closure-approximate-lower-bound.stderr
index baf223b786b08..3e5e4868341ed 100644
--- a/src/test/ui/nll/ty-outlives/ty-param-closure-approximate-lower-bound.stderr
+++ b/src/test/ui/nll/ty-outlives/ty-param-closure-approximate-lower-bound.stderr
@@ -52,10 +52,10 @@ LL | | }
 error[E0309]: the parameter type `T` may not live long enough
   --> $DIR/ty-param-closure-approximate-lower-bound.rs:29:24
    |
+LL | fn generic_fail<'a, T>(cell: Cell<&'a ()>, value: T) {
+   |                     - help: consider adding an explicit lifetime bound...: `T: 'a`
 LL |     twice(cell, value, |a, b| invoke(a, b));
-   |                        ^^^^^^^^^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'a`...
+   |                        ^^^^^^^^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/nll/ty-outlives/ty-param-closure-outlives-from-return-type.stderr b/src/test/ui/nll/ty-outlives/ty-param-closure-outlives-from-return-type.stderr
index 88d73e7a729a9..dc2f23b4fc8a3 100644
--- a/src/test/ui/nll/ty-outlives/ty-param-closure-outlives-from-return-type.stderr
+++ b/src/test/ui/nll/ty-outlives/ty-param-closure-outlives-from-return-type.stderr
@@ -29,18 +29,20 @@ LL | | }
 error[E0309]: the parameter type `T` may not live long enough
   --> $DIR/ty-param-closure-outlives-from-return-type.rs:26:23
    |
+LL | fn no_region<'a, T>(x: Box<T>) -> Box<dyn Debug + 'a>
+   |                  - help: consider adding an explicit lifetime bound...: `T: 'a`
+...
 LL |     with_signature(x, |y| y)
-   |                       ^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'a`...
+   |                       ^^^^^ ...so that the type `T` will meet its required lifetime bounds
 
 error[E0309]: the parameter type `T` may not live long enough
   --> $DIR/ty-param-closure-outlives-from-return-type.rs:41:5
    |
+LL | fn wrong_region<'a, 'b, T>(x: Box<T>) -> Box<Debug + 'a>
+   |                         - help: consider adding an explicit lifetime bound...: `T: 'a`
+...
 LL |     x
-   |     ^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'a`...
+   |     ^ ...so that the type `T` will meet its required lifetime bounds
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/nll/ty-outlives/ty-param-closure-outlives-from-where-clause.stderr b/src/test/ui/nll/ty-outlives/ty-param-closure-outlives-from-where-clause.stderr
index 5b175aac1e1cb..e9f728c77b34b 100644
--- a/src/test/ui/nll/ty-outlives/ty-param-closure-outlives-from-where-clause.stderr
+++ b/src/test/ui/nll/ty-outlives/ty-param-closure-outlives-from-where-clause.stderr
@@ -37,6 +37,8 @@ LL | | }
 error[E0309]: the parameter type `T` may not live long enough
   --> $DIR/ty-param-closure-outlives-from-where-clause.rs:27:26
    |
+LL |   fn no_region<'a, T>(a: Cell<&'a ()>, b: T) {
+   |                    - help: consider adding an explicit lifetime bound...: `T: 'a`
 LL |       with_signature(a, b, |x, y| {
    |  __________________________^
 LL | |
@@ -45,9 +47,7 @@ LL | |         // See `correct_region`, which explains the point of this
 ...  |
 LL | |         require(&x, &y)
 LL | |     })
-   | |_____^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'a`...
+   | |_____^ ...so that the type `T` will meet its required lifetime bounds
 
 note: external requirements
   --> $DIR/ty-param-closure-outlives-from-where-clause.rs:43:26
@@ -121,15 +121,16 @@ LL | | }
 error[E0309]: the parameter type `T` may not live long enough
   --> $DIR/ty-param-closure-outlives-from-where-clause.rs:64:26
    |
+LL |   fn wrong_region<'a, 'b, T>(a: Cell<&'a ()>, b: T)
+   |                           - help: consider adding an explicit lifetime bound...: `T: 'a`
+...
 LL |       with_signature(a, b, |x, y| {
    |  __________________________^
 LL | |
 LL | |         // See `correct_region`
 LL | |         require(&x, &y)
 LL | |     })
-   | |_____^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'a`...
+   | |_____^ ...so that the type `T` will meet its required lifetime bounds
 
 note: external requirements
   --> $DIR/ty-param-closure-outlives-from-where-clause.rs:77:26
diff --git a/src/test/ui/nll/ty-outlives/ty-param-fn-body.stderr b/src/test/ui/nll/ty-outlives/ty-param-fn-body.stderr
index 9a023a0e58e5f..a2e6a5d57cd62 100644
--- a/src/test/ui/nll/ty-outlives/ty-param-fn-body.stderr
+++ b/src/test/ui/nll/ty-outlives/ty-param-fn-body.stderr
@@ -1,10 +1,10 @@
 error[E0309]: the parameter type `T` may not live long enough
   --> $DIR/ty-param-fn-body.rs:19:5
    |
+LL | fn region_static<'a, T>(cell: Cell<&'a usize>, t: T) {
+   |                      - help: consider adding an explicit lifetime bound...: `T: 'a`
 LL |     outlives(cell, t)
-   |     ^^^^^^^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'a`...
+   |     ^^^^^^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/nll/ty-outlives/ty-param-fn.stderr b/src/test/ui/nll/ty-outlives/ty-param-fn.stderr
index 8c8529620d57f..fce360dd54bfb 100644
--- a/src/test/ui/nll/ty-outlives/ty-param-fn.stderr
+++ b/src/test/ui/nll/ty-outlives/ty-param-fn.stderr
@@ -1,18 +1,20 @@
 error[E0309]: the parameter type `T` may not live long enough
   --> $DIR/ty-param-fn.rs:11:5
    |
+LL | fn no_region<'a, T>(x: Box<T>) -> Box<Debug + 'a>
+   |                  - help: consider adding an explicit lifetime bound...: `T: 'a`
+...
 LL |     x
-   |     ^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'a`...
+   |     ^ ...so that the type `T` will meet its required lifetime bounds
 
 error[E0309]: the parameter type `T` may not live long enough
   --> $DIR/ty-param-fn.rs:26:5
    |
+LL | fn wrong_region<'a, 'b, T>(x: Box<T>) -> Box<Debug + 'a>
+   |                         - help: consider adding an explicit lifetime bound...: `T: 'a`
+...
 LL |     x
-   |     ^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'a`...
+   |     ^ ...so that the type `T` will meet its required lifetime bounds
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/regions/regions-close-associated-type-into-object.nll.stderr b/src/test/ui/regions/regions-close-associated-type-into-object.nll.stderr
index 92c4956da02d2..f7dcaa9d97e7c 100644
--- a/src/test/ui/regions/regions-close-associated-type-into-object.nll.stderr
+++ b/src/test/ui/regions/regions-close-associated-type-into-object.nll.stderr
@@ -5,6 +5,7 @@ LL |     Box::new(item)
    |     ^^^^^^^^^^^^^^
    |
    = help: consider adding an explicit lifetime bound `<T as Iter>::Item: 'static`...
+   = note: ...so that the type `<T as Iter>::Item` will meet its required lifetime bounds
 
 error[E0310]: the associated type `<T as Iter>::Item` may not live long enough
   --> $DIR/regions-close-associated-type-into-object.rs:22:5
@@ -13,6 +14,7 @@ LL |     Box::new(item)
    |     ^^^^^^^^^^^^^^
    |
    = help: consider adding an explicit lifetime bound `<T as Iter>::Item: 'static`...
+   = note: ...so that the type `<T as Iter>::Item` will meet its required lifetime bounds
 
 error[E0309]: the associated type `<T as Iter>::Item` may not live long enough
   --> $DIR/regions-close-associated-type-into-object.rs:28:5
@@ -21,6 +23,7 @@ LL |     Box::new(item)
    |     ^^^^^^^^^^^^^^
    |
    = help: consider adding an explicit lifetime bound `<T as Iter>::Item: 'a`...
+   = note: ...so that the type `<T as Iter>::Item` will meet its required lifetime bounds
 
 error[E0309]: the associated type `<T as Iter>::Item` may not live long enough
   --> $DIR/regions-close-associated-type-into-object.rs:35:5
@@ -29,6 +32,7 @@ LL |     Box::new(item)
    |     ^^^^^^^^^^^^^^
    |
    = help: consider adding an explicit lifetime bound `<T as Iter>::Item: 'a`...
+   = note: ...so that the type `<T as Iter>::Item` will meet its required lifetime bounds
 
 error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/regions/regions-close-object-into-object-4.nll.stderr b/src/test/ui/regions/regions-close-object-into-object-4.nll.stderr
index b30626830ad6b..6a2429e51ecda 100644
--- a/src/test/ui/regions/regions-close-object-into-object-4.nll.stderr
+++ b/src/test/ui/regions/regions-close-object-into-object-4.nll.stderr
@@ -1,26 +1,26 @@
 error[E0310]: the parameter type `U` may not live long enough
   --> $DIR/regions-close-object-into-object-4.rs:9:5
    |
+LL | fn i<'a, T, U>(v: Box<dyn A<U>+'a>) -> Box<dyn X + 'static> {
+   |             - help: consider adding an explicit lifetime bound...: `U: 'static`
 LL |     Box::new(B(&*v)) as Box<dyn X>
-   |     ^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `U: 'static`...
+   |     ^^^^^^^^ ...so that the type `U` will meet its required lifetime bounds
 
 error[E0310]: the parameter type `U` may not live long enough
   --> $DIR/regions-close-object-into-object-4.rs:9:5
    |
+LL | fn i<'a, T, U>(v: Box<dyn A<U>+'a>) -> Box<dyn X + 'static> {
+   |             - help: consider adding an explicit lifetime bound...: `U: 'static`
 LL |     Box::new(B(&*v)) as Box<dyn X>
-   |     ^^^^^^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `U: 'static`...
+   |     ^^^^^^^^^^^^^^^^ ...so that the type `U` will meet its required lifetime bounds
 
 error[E0310]: the parameter type `U` may not live long enough
   --> $DIR/regions-close-object-into-object-4.rs:9:5
    |
+LL | fn i<'a, T, U>(v: Box<dyn A<U>+'a>) -> Box<dyn X + 'static> {
+   |             - help: consider adding an explicit lifetime bound...: `U: 'static`
 LL |     Box::new(B(&*v)) as Box<dyn X>
-   |     ^^^^^^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `U: 'static`...
+   |     ^^^^^^^^^^^^^^^^ ...so that the type `U` will meet its required lifetime bounds
 
 error: lifetime may not live long enough
   --> $DIR/regions-close-object-into-object-4.rs:9:5
@@ -42,10 +42,10 @@ LL |     Box::new(B(&*v)) as Box<dyn X>
 error[E0310]: the parameter type `U` may not live long enough
   --> $DIR/regions-close-object-into-object-4.rs:9:14
    |
+LL | fn i<'a, T, U>(v: Box<dyn A<U>+'a>) -> Box<dyn X + 'static> {
+   |             - help: consider adding an explicit lifetime bound...: `U: 'static`
 LL |     Box::new(B(&*v)) as Box<dyn X>
-   |              ^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `U: 'static`...
+   |              ^^^^^^ ...so that the type `U` will meet its required lifetime bounds
 
 error: aborting due to 6 previous errors
 
diff --git a/src/test/ui/regions/regions-close-object-into-object-5.nll.stderr b/src/test/ui/regions/regions-close-object-into-object-5.nll.stderr
index 7486e73e66ab3..54302cc6dca22 100644
--- a/src/test/ui/regions/regions-close-object-into-object-5.nll.stderr
+++ b/src/test/ui/regions/regions-close-object-into-object-5.nll.stderr
@@ -1,26 +1,29 @@
 error[E0310]: the parameter type `T` may not live long enough
   --> $DIR/regions-close-object-into-object-5.rs:17:5
    |
+LL | fn f<'a, T, U>(v: Box<A<T> + 'static>) -> Box<X + 'static> {
+   |          - help: consider adding an explicit lifetime bound...: `T: 'static`
+LL |     // oh dear!
 LL |     Box::new(B(&*v)) as Box<dyn X>
-   |     ^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'static`...
+   |     ^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds
 
 error[E0310]: the parameter type `T` may not live long enough
   --> $DIR/regions-close-object-into-object-5.rs:17:5
    |
+LL | fn f<'a, T, U>(v: Box<A<T> + 'static>) -> Box<X + 'static> {
+   |          - help: consider adding an explicit lifetime bound...: `T: 'static`
+LL |     // oh dear!
 LL |     Box::new(B(&*v)) as Box<dyn X>
-   |     ^^^^^^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'static`...
+   |     ^^^^^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds
 
 error[E0310]: the parameter type `T` may not live long enough
   --> $DIR/regions-close-object-into-object-5.rs:17:5
    |
+LL | fn f<'a, T, U>(v: Box<A<T> + 'static>) -> Box<X + 'static> {
+   |          - help: consider adding an explicit lifetime bound...: `T: 'static`
+LL |     // oh dear!
 LL |     Box::new(B(&*v)) as Box<dyn X>
-   |     ^^^^^^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'static`...
+   |     ^^^^^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds
 
 error[E0515]: cannot return value referencing local data `*v`
   --> $DIR/regions-close-object-into-object-5.rs:17:5
@@ -34,10 +37,11 @@ LL |     Box::new(B(&*v)) as Box<dyn X>
 error[E0310]: the parameter type `T` may not live long enough
   --> $DIR/regions-close-object-into-object-5.rs:17:14
    |
+LL | fn f<'a, T, U>(v: Box<A<T> + 'static>) -> Box<X + 'static> {
+   |          - help: consider adding an explicit lifetime bound...: `T: 'static`
+LL |     // oh dear!
 LL |     Box::new(B(&*v)) as Box<dyn X>
-   |              ^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'static`...
+   |              ^^^^^^ ...so that the type `T` will meet its required lifetime bounds
 
 error: aborting due to 5 previous errors
 
diff --git a/src/test/ui/regions/regions-close-over-type-parameter-1.nll.stderr b/src/test/ui/regions/regions-close-over-type-parameter-1.nll.stderr
index b576ae8701137..063c3b19a19cc 100644
--- a/src/test/ui/regions/regions-close-over-type-parameter-1.nll.stderr
+++ b/src/test/ui/regions/regions-close-over-type-parameter-1.nll.stderr
@@ -1,18 +1,18 @@
 error[E0310]: the parameter type `A` may not live long enough
   --> $DIR/regions-close-over-type-parameter-1.rs:12:5
    |
+LL | fn make_object1<A: SomeTrait>(v: A) -> Box<dyn SomeTrait + 'static> {
+   |                 -- help: consider adding an explicit lifetime bound...: `A: 'static +`
 LL |     Box::new(v) as Box<dyn SomeTrait + 'static>
-   |     ^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `A: 'static`...
+   |     ^^^^^^^^^^^ ...so that the type `A` will meet its required lifetime bounds
 
 error[E0309]: the parameter type `A` may not live long enough
   --> $DIR/regions-close-over-type-parameter-1.rs:21:5
    |
+LL | fn make_object3<'a, 'b, A: SomeTrait + 'a>(v: A) -> Box<dyn SomeTrait + 'b> {
+   |                         -- help: consider adding an explicit lifetime bound...: `A: 'b +`
 LL |     Box::new(v) as Box<dyn SomeTrait + 'b>
-   |     ^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `A: 'b`...
+   |     ^^^^^^^^^^^ ...so that the type `A` will meet its required lifetime bounds
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/regions/regions-close-param-into-object.nll.stderr b/src/test/ui/regions/regions-close-param-into-object.nll.stderr
index 7bd7824f00a46..f0464e299bbec 100644
--- a/src/test/ui/regions/regions-close-param-into-object.nll.stderr
+++ b/src/test/ui/regions/regions-close-param-into-object.nll.stderr
@@ -1,34 +1,38 @@
 error[E0310]: the parameter type `T` may not live long enough
   --> $DIR/regions-close-param-into-object.rs:6:5
    |
+LL | fn p1<T>(v: T) -> Box<dyn X + 'static>
+   |       - help: consider adding an explicit lifetime bound...: `T: 'static`
+...
 LL |     Box::new(v)
-   |     ^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'static`...
+   |     ^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds
 
 error[E0310]: the parameter type `T` may not live long enough
   --> $DIR/regions-close-param-into-object.rs:12:5
    |
+LL | fn p2<T>(v: Box<T>) -> Box<dyn X + 'static>
+   |       - help: consider adding an explicit lifetime bound...: `T: 'static`
+...
 LL |     Box::new(v)
-   |     ^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'static`...
+   |     ^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds
 
 error[E0309]: the parameter type `T` may not live long enough
   --> $DIR/regions-close-param-into-object.rs:18:5
    |
+LL | fn p3<'a,T>(v: T) -> Box<dyn X + 'a>
+   |          - help: consider adding an explicit lifetime bound...: `T: 'a`
+...
 LL |     Box::new(v)
-   |     ^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'a`...
+   |     ^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds
 
 error[E0309]: the parameter type `T` may not live long enough
   --> $DIR/regions-close-param-into-object.rs:24:5
    |
+LL | fn p4<'a,T>(v: Box<T>) -> Box<dyn X + 'a>
+   |          - help: consider adding an explicit lifetime bound...: `T: 'a`
+...
 LL |     Box::new(v)
-   |     ^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'a`...
+   |     ^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds
 
 error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/regions/regions-implied-bounds-projection-gap-1.nll.stderr b/src/test/ui/regions/regions-implied-bounds-projection-gap-1.nll.stderr
index 0f0f86dfcdd69..0e1db8acf1fae 100644
--- a/src/test/ui/regions/regions-implied-bounds-projection-gap-1.nll.stderr
+++ b/src/test/ui/regions/regions-implied-bounds-projection-gap-1.nll.stderr
@@ -1,10 +1,11 @@
 error[E0309]: the parameter type `T` may not live long enough
   --> $DIR/regions-implied-bounds-projection-gap-1.rs:16:5
    |
+LL | fn func<'x, T:Trait1<'x>>(t: &'x T::Foo)
+   |             -- help: consider adding an explicit lifetime bound...: `T: 'x +`
+LL | {
 LL |     wf::<&'x T>();
-   |     ^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'x`...
+   |     ^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/regions/regions-infer-bound-from-trait-self.nll.stderr b/src/test/ui/regions/regions-infer-bound-from-trait-self.nll.stderr
index 0651e305cde35..e88f79a3a8c54 100644
--- a/src/test/ui/regions/regions-infer-bound-from-trait-self.nll.stderr
+++ b/src/test/ui/regions/regions-infer-bound-from-trait-self.nll.stderr
@@ -5,6 +5,7 @@ LL |         check_bound(x, self)
    |         ^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider adding an explicit lifetime bound `Self: 'a`...
+   = note: ...so that the type `Self` will meet its required lifetime bounds
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/regions/regions-infer-bound-from-trait.nll.stderr b/src/test/ui/regions/regions-infer-bound-from-trait.nll.stderr
index 1f7b34fc69962..fe07749954404 100644
--- a/src/test/ui/regions/regions-infer-bound-from-trait.nll.stderr
+++ b/src/test/ui/regions/regions-infer-bound-from-trait.nll.stderr
@@ -1,18 +1,18 @@
 error[E0309]: the parameter type `A` may not live long enough
   --> $DIR/regions-infer-bound-from-trait.rs:33:5
    |
+LL | fn bar1<'a,A>(x: Inv<'a>, a: A) {
+   |            - help: consider adding an explicit lifetime bound...: `A: 'a`
 LL |     check_bound(x, a)
-   |     ^^^^^^^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `A: 'a`...
+   |     ^^^^^^^^^^^^^^^^^ ...so that the type `A` will meet its required lifetime bounds
 
 error[E0309]: the parameter type `A` may not live long enough
   --> $DIR/regions-infer-bound-from-trait.rs:37:5
    |
+LL | fn bar2<'a,'b,A:Is<'b>>(x: Inv<'a>, y: Inv<'b>, a: A) {
+   |               -- help: consider adding an explicit lifetime bound...: `A: 'a +`
 LL |     check_bound(x, a)
-   |     ^^^^^^^^^^^^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `A: 'a`...
+   |     ^^^^^^^^^^^^^^^^^ ...so that the type `A` will meet its required lifetime bounds
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/suggestions/lifetimes/missing-lifetimes-in-signature-2.nll.stderr b/src/test/ui/suggestions/lifetimes/missing-lifetimes-in-signature-2.nll.stderr
index 536494c73445c..d38d66c08853c 100644
--- a/src/test/ui/suggestions/lifetimes/missing-lifetimes-in-signature-2.nll.stderr
+++ b/src/test/ui/suggestions/lifetimes/missing-lifetimes-in-signature-2.nll.stderr
@@ -1,6 +1,8 @@
 error[E0311]: the parameter type `T` may not live long enough
   --> $DIR/missing-lifetimes-in-signature-2.rs:20:5
    |
+LL |   fn func<T: Test>(foo: &Foo, t: T) {
+   |           -- help: consider adding an explicit lifetime bound...: `T: 'a +`
 LL | /     foo.bar(move |_| {
 LL | |
 LL | |         t.test();
@@ -12,6 +14,14 @@ note: the parameter type `T` must be valid for the anonymous lifetime defined he
    |
 LL | fn func<T: Test>(foo: &Foo, t: T) {
    |                        ^^^
+note: ...so that the type `T` will meet its required lifetime bounds
+  --> $DIR/missing-lifetimes-in-signature-2.rs:20:5
+   |
+LL | /     foo.bar(move |_| {
+LL | |
+LL | |         t.test();
+LL | |     });
+   | |______^
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/suggestions/lifetimes/missing-lifetimes-in-signature.nll.stderr b/src/test/ui/suggestions/lifetimes/missing-lifetimes-in-signature.nll.stderr
index 0ae629676fec7..4a18e0a4f8bbd 100644
--- a/src/test/ui/suggestions/lifetimes/missing-lifetimes-in-signature.nll.stderr
+++ b/src/test/ui/suggestions/lifetimes/missing-lifetimes-in-signature.nll.stderr
@@ -26,6 +26,9 @@ LL | fn foo<G, T>(g: G, dest: &mut T) -> impl FnOnce() + '_
 error[E0311]: the parameter type `G` may not live long enough
   --> $DIR/missing-lifetimes-in-signature.rs:32:5
    |
+LL |   fn bar<G, T>(g: G, dest: &mut T) -> impl FnOnce() + '_
+   |          - help: consider adding an explicit lifetime bound...: `G: 'a`
+...
 LL | /     move || {
 LL | |         *dest = g.get();
 LL | |     }
@@ -36,10 +39,20 @@ note: the parameter type `G` must be valid for the anonymous lifetime defined he
    |
 LL | fn bar<G, T>(g: G, dest: &mut T) -> impl FnOnce() + '_
    |                          ^^^^^^
+note: ...so that the type `G` will meet its required lifetime bounds
+  --> $DIR/missing-lifetimes-in-signature.rs:32:5
+   |
+LL | /     move || {
+LL | |         *dest = g.get();
+LL | |     }
+   | |_____^
 
 error[E0311]: the parameter type `G` may not live long enough
   --> $DIR/missing-lifetimes-in-signature.rs:55:5
    |
+LL |   fn qux<'a, G: 'a, T>(g: G, dest: &mut T) -> impl FnOnce() + '_
+   |              -- help: consider adding an explicit lifetime bound...: `G: 'b +`
+...
 LL | /     move || {
 LL | |         *dest = g.get();
 LL | |     }
@@ -50,10 +63,20 @@ note: the parameter type `G` must be valid for the anonymous lifetime defined he
    |
 LL | fn qux<'a, G: 'a, T>(g: G, dest: &mut T) -> impl FnOnce() + '_
    |                                  ^^^^^^
+note: ...so that the type `G` will meet its required lifetime bounds
+  --> $DIR/missing-lifetimes-in-signature.rs:55:5
+   |
+LL | /     move || {
+LL | |         *dest = g.get();
+LL | |     }
+   | |_____^
 
 error[E0311]: the parameter type `G` may not live long enough
   --> $DIR/missing-lifetimes-in-signature.rs:65:9
    |
+LL |       fn qux<'b, G: Get<T> + 'b, T>(g: G, dest: &mut T) -> impl FnOnce() + '_ {
+   |                  -- help: consider adding an explicit lifetime bound...: `G: 'c +`
+...
 LL | /         move || {
 LL | |             *dest = g.get();
 LL | |         }
@@ -64,10 +87,20 @@ note: the parameter type `G` must be valid for the anonymous lifetime defined he
    |
 LL |     fn qux<'b, G: Get<T> + 'b, T>(g: G, dest: &mut T) -> impl FnOnce() + '_ {
    |                                               ^^^^^^
+note: ...so that the type `G` will meet its required lifetime bounds
+  --> $DIR/missing-lifetimes-in-signature.rs:65:9
+   |
+LL | /         move || {
+LL | |             *dest = g.get();
+LL | |         }
+   | |_________^
 
 error[E0311]: the parameter type `G` may not live long enough
   --> $DIR/missing-lifetimes-in-signature.rs:77:5
    |
+LL |   fn bat<'a, G: 'a, T>(g: G, dest: &mut T) -> impl FnOnce() + '_ + 'a
+   |              -- help: consider adding an explicit lifetime bound...: `G: 'b +`
+...
 LL | /     move || {
 LL | |         *dest = g.get();
 LL | |     }
@@ -78,6 +111,13 @@ note: the parameter type `G` must be valid for the anonymous lifetime defined he
    |
 LL | fn bat<'a, G: 'a, T>(g: G, dest: &mut T) -> impl FnOnce() + '_ + 'a
    |                                  ^^^^^^
+note: ...so that the type `G` will meet its required lifetime bounds
+  --> $DIR/missing-lifetimes-in-signature.rs:77:5
+   |
+LL | /     move || {
+LL | |         *dest = g.get();
+LL | |     }
+   | |_____^
 
 error[E0621]: explicit lifetime required in the type of `dest`
   --> $DIR/missing-lifetimes-in-signature.rs:77:5
@@ -93,12 +133,13 @@ LL | |     }
 error[E0309]: the parameter type `G` may not live long enough
   --> $DIR/missing-lifetimes-in-signature.rs:89:5
    |
+LL |   fn bak<'a, G, T>(g: G, dest: &'a mut T) -> impl FnOnce() + 'a
+   |              - help: consider adding an explicit lifetime bound...: `G: 'a`
+...
 LL | /     move || {
 LL | |         *dest = g.get();
 LL | |     }
-   | |_____^
-   |
-   = help: consider adding an explicit lifetime bound `G: 'a`...
+   | |_____^ ...so that the type `G` will meet its required lifetime bounds
 
 error: aborting due to 8 previous errors
 
diff --git a/src/test/ui/suggestions/suggest-impl-trait-lifetime.nll.stderr b/src/test/ui/suggestions/suggest-impl-trait-lifetime.nll.stderr
index f4eb9813c1ac7..72354eaaee147 100644
--- a/src/test/ui/suggestions/suggest-impl-trait-lifetime.nll.stderr
+++ b/src/test/ui/suggestions/suggest-impl-trait-lifetime.nll.stderr
@@ -1,10 +1,11 @@
 error[E0310]: the parameter type `impl Debug` may not live long enough
   --> $DIR/suggest-impl-trait-lifetime.rs:7:5
    |
+LL | fn foo(d: impl Debug) {
+   |           ---------- help: consider adding an explicit lifetime bound...: `impl Debug + 'static`
+LL |
 LL |     bar(d);
-   |     ^^^^^^
-   |
-   = help: consider adding an explicit lifetime bound `impl Debug: 'static`...
+   |     ^^^^^^ ...so that the type `impl Debug` will meet its required lifetime bounds
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/type-alias-impl-trait/generic_type_does_not_live_long_enough.nll.stderr b/src/test/ui/type-alias-impl-trait/generic_type_does_not_live_long_enough.nll.stderr
index db771d211322c..a3b410c2cfb8c 100644
--- a/src/test/ui/type-alias-impl-trait/generic_type_does_not_live_long_enough.nll.stderr
+++ b/src/test/ui/type-alias-impl-trait/generic_type_does_not_live_long_enough.nll.stderr
@@ -19,10 +19,10 @@ LL | type WrongGeneric<T> = impl 'static;
 error[E0310]: the parameter type `T` may not live long enough
   --> $DIR/generic_type_does_not_live_long_enough.rs:18:5
    |
+LL | fn wrong_generic<T>(t: T) -> WrongGeneric<T> {
+   |                  - help: consider adding an explicit lifetime bound...: `T: 'static`
 LL |     t
-   |     ^
-   |
-   = help: consider adding an explicit lifetime bound `T: 'static`...
+   |     ^ ...so that the type `T` will meet its required lifetime bounds
 
 error: aborting due to 3 previous errors
 
diff --git a/src/tools/compiletest/src/common.rs b/src/tools/compiletest/src/common.rs
index 1bf6e6d011e5c..2cb368c688188 100644
--- a/src/tools/compiletest/src/common.rs
+++ b/src/tools/compiletest/src/common.rs
@@ -198,11 +198,8 @@ pub struct Config {
     /// The rust-demangler executable.
     pub rust_demangler_path: Option<PathBuf>,
 
-    /// The Python executable to use for LLDB.
-    pub lldb_python: String,
-
-    /// The Python executable to use for htmldocck.
-    pub docck_python: String,
+    /// The Python executable to use for LLDB and htmldocck.
+    pub python: String,
 
     /// The jsondocck executable.
     pub jsondocck_path: Option<String>,
diff --git a/src/tools/compiletest/src/header/tests.rs b/src/tools/compiletest/src/header/tests.rs
index 5b144a1020f4c..a8fd4880f0782 100644
--- a/src/tools/compiletest/src/header/tests.rs
+++ b/src/tools/compiletest/src/header/tests.rs
@@ -43,8 +43,7 @@ fn config() -> Config {
         "--compile-lib-path=",
         "--run-lib-path=",
         "--rustc-path=",
-        "--lldb-python=",
-        "--docck-python=",
+        "--python=",
         "--jsondocck-path=",
         "--src-base=",
         "--build-base=",
diff --git a/src/tools/compiletest/src/main.rs b/src/tools/compiletest/src/main.rs
index 8c1f28f140768..f4e6c2a2bb288 100644
--- a/src/tools/compiletest/src/main.rs
+++ b/src/tools/compiletest/src/main.rs
@@ -61,8 +61,7 @@ pub fn parse_config(args: Vec<String>) -> Config {
         .reqopt("", "rustc-path", "path to rustc to use for compiling", "PATH")
         .optopt("", "rustdoc-path", "path to rustdoc to use for compiling", "PATH")
         .optopt("", "rust-demangler-path", "path to rust-demangler to use in tests", "PATH")
-        .reqopt("", "lldb-python", "path to python to use for doc tests", "PATH")
-        .reqopt("", "docck-python", "path to python to use for doc tests", "PATH")
+        .reqopt("", "python", "path to python to use for doc tests", "PATH")
         .optopt("", "jsondocck-path", "path to jsondocck to use for doc tests", "PATH")
         .optopt("", "valgrind-path", "path to Valgrind executable for Valgrind tests", "PROGRAM")
         .optflag("", "force-valgrind", "fail if Valgrind tests cannot be run under Valgrind")
@@ -222,8 +221,7 @@ pub fn parse_config(args: Vec<String>) -> Config {
         rustc_path: opt_path(matches, "rustc-path"),
         rustdoc_path: matches.opt_str("rustdoc-path").map(PathBuf::from),
         rust_demangler_path: matches.opt_str("rust-demangler-path").map(PathBuf::from),
-        lldb_python: matches.opt_str("lldb-python").unwrap(),
-        docck_python: matches.opt_str("docck-python").unwrap(),
+        python: matches.opt_str("python").unwrap(),
         jsondocck_path: matches.opt_str("jsondocck-path"),
         valgrind_path: matches.opt_str("valgrind-path"),
         force_valgrind: matches.opt_present("force-valgrind"),
diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index 6b27d1ecbf550..aedddedac6184 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -179,7 +179,7 @@ pub fn compute_stamp_hash(config: &Config) -> String {
         }
 
         Some(Debugger::Lldb) => {
-            config.lldb_python.hash(&mut hash);
+            config.python.hash(&mut hash);
             config.lldb_python_dir.hash(&mut hash);
             env::var_os("PATH").hash(&mut hash);
             env::var_os("PYTHONPATH").hash(&mut hash);
@@ -1141,7 +1141,7 @@ impl<'test> TestCx<'test> {
         // Prepare the lldb_batchmode which executes the debugger script
         let lldb_script_path = rust_src_root.join("src/etc/lldb_batchmode.py");
         self.cmd2procres(
-            Command::new(&self.config.lldb_python)
+            Command::new(&self.config.python)
                 .arg(&lldb_script_path)
                 .arg(test_executable)
                 .arg(debugger_script)
@@ -2256,7 +2256,7 @@ impl<'test> TestCx<'test> {
             self.check_rustdoc_test_option(proc_res);
         } else {
             let root = self.config.find_rust_src_root().unwrap();
-            let mut cmd = Command::new(&self.config.docck_python);
+            let mut cmd = Command::new(&self.config.python);
             cmd.arg(root.join("src/etc/htmldocck.py")).arg(&out_dir).arg(&self.testpaths.file);
             if self.config.bless {
                 cmd.arg("--bless");
@@ -2457,7 +2457,7 @@ impl<'test> TestCx<'test> {
         let mut json_out = out_dir.join(self.testpaths.file.file_stem().unwrap());
         json_out.set_extension("json");
         let res = self.cmd2procres(
-            Command::new(&self.config.docck_python)
+            Command::new(&self.config.python)
                 .arg(root.join("src/etc/check_missing_items.py"))
                 .arg(&json_out),
         );
@@ -2852,7 +2852,7 @@ impl<'test> TestCx<'test> {
             .stdout(Stdio::piped())
             .stderr(Stdio::piped())
             .env("TARGET", &self.config.target)
-            .env("PYTHON", &self.config.docck_python)
+            .env("PYTHON", &self.config.python)
             .env("S", src_root)
             .env("RUST_BUILD_STAGE", &self.config.stage_id)
             .env("RUSTC", cwd.join(&self.config.rustc_path))