diff --git a/compiler/rustc_ast/Cargo.toml b/compiler/rustc_ast/Cargo.toml
index c24180bacfc1b..fcbf968182504 100644
--- a/compiler/rustc_ast/Cargo.toml
+++ b/compiler/rustc_ast/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 bitflags = "1.2.1"
diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
index 94137391568c9..46886c518afd5 100644
--- a/compiler/rustc_ast_lowering/src/expr.rs
+++ b/compiler/rustc_ast_lowering/src/expr.rs
@@ -1609,11 +1609,11 @@ impl<'hir> LoweringContext<'_, 'hir> {
     }
 
     /// Desugar `ExprKind::Yeet` from: `do yeet <expr>` into:
-    /// ```rust
+    /// ```ignore(illustrative)
     /// // If there is an enclosing `try {...}`:
-    /// break 'catch_target FromResidual::from_residual(Yeet(residual)),
+    /// break 'catch_target FromResidual::from_residual(Yeet(residual));
     /// // Otherwise:
-    /// return FromResidual::from_residual(Yeet(residual)),
+    /// return FromResidual::from_residual(Yeet(residual));
     /// ```
     /// But to simplify this, there's a `from_yeet` lang item function which
     /// handles the combined `FromResidual::from_residual(Yeet(residual))`.
diff --git a/compiler/rustc_ast_pretty/Cargo.toml b/compiler/rustc_ast_pretty/Cargo.toml
index 5ad8714e9fec9..a3e3e823b08eb 100644
--- a/compiler/rustc_ast_pretty/Cargo.toml
+++ b/compiler/rustc_ast_pretty/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 rustc_span = { path = "../rustc_span" }
diff --git a/compiler/rustc_attr/Cargo.toml b/compiler/rustc_attr/Cargo.toml
index ba310a6860e82..6349ddf31d10b 100644
--- a/compiler/rustc_attr/Cargo.toml
+++ b/compiler/rustc_attr/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 rustc_ast_pretty = { path = "../rustc_ast_pretty" }
diff --git a/compiler/rustc_borrowck/Cargo.toml b/compiler/rustc_borrowck/Cargo.toml
index fbf628e865e2c..87c113f3e30b7 100644
--- a/compiler/rustc_borrowck/Cargo.toml
+++ b/compiler/rustc_borrowck/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 either = "1.5.0"
diff --git a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
index 43d67bfa72991..038cae9a3ede2 100644
--- a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
@@ -341,7 +341,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
     /// Report an error because the universal region `fr` was required to outlive
     /// `outlived_fr` but it is not known to do so. For example:
     ///
-    /// ```compile_fail,E0312
+    /// ```compile_fail
     /// fn foo<'a, 'b>(x: &'a u32) -> &'b u32 { x }
     /// ```
     ///
diff --git a/compiler/rustc_borrowck/src/region_infer/mod.rs b/compiler/rustc_borrowck/src/region_infer/mod.rs
index 244e6e3422d83..3410f260b2f3b 100644
--- a/compiler/rustc_borrowck/src/region_infer/mod.rs
+++ b/compiler/rustc_borrowck/src/region_infer/mod.rs
@@ -1398,7 +1398,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     /// whether any of the constraints were too strong. In particular,
     /// we want to check for a case where a universally quantified
     /// region exceeded its bounds. Consider:
-    /// ```compile_fail,E0312
+    /// ```compile_fail
     /// fn foo<'a, 'b>(x: &'a u32) -> &'b u32 { x }
     /// ```
     /// In this case, returning `x` requires `&'a u32 <: &'b u32`
@@ -1451,7 +1451,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     /// <https://smallcultfollowing.com/babysteps/blog/2019/01/17/polonius-and-region-errors/>
     ///
     /// In the canonical example
-    /// ```compile_fail,E0312
+    /// ```compile_fail
     /// fn foo<'a, 'b>(x: &'a u32) -> &'b u32 { x }
     /// ```
     /// returning `x` requires `&'a u32 <: &'b u32` and hence we establish (transitively) a
diff --git a/compiler/rustc_builtin_macros/src/assert/context.rs b/compiler/rustc_builtin_macros/src/assert/context.rs
index 973a8cb85c2b9..bb6839360262a 100644
--- a/compiler/rustc_builtin_macros/src/assert/context.rs
+++ b/compiler/rustc_builtin_macros/src/assert/context.rs
@@ -58,6 +58,7 @@ impl<'cx, 'a> Context<'cx, 'a> {
     /// Builds the whole `assert!` expression. For example, `let elem = 1; assert!(elem == 1);` expands to:
     ///
     /// ```rust
+    /// #![feature(generic_assert_internals)]
     /// let elem = 1;
     /// {
     ///   #[allow(unused_imports)]
@@ -70,7 +71,7 @@ impl<'cx, 'a> Context<'cx, 'a> {
     ///       __local_bind0
     ///     } == 1
     ///   ) {
-    ///     panic!("Assertion failed: elem == 1\nWith captures:\n  elem = {}", __capture0)
+    ///     panic!("Assertion failed: elem == 1\nWith captures:\n  elem = {:?}", __capture0)
     ///   }
     /// }
     /// ```
diff --git a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
index 6fbd99b5c71c5..a794fdf2bba7b 100644
--- a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
@@ -1114,6 +1114,11 @@ impl<'a> MethodDef<'a> {
     /// ```
     /// is equivalent to:
     /// ```
+    /// #![feature(core_intrinsics)]
+    /// enum A {
+    ///     A1,
+    ///     A2(i32)
+    /// }
     /// impl ::core::cmp::PartialEq for A {
     ///     #[inline]
     ///     fn eq(&self, other: &A) -> bool {
diff --git a/compiler/rustc_codegen_llvm/Cargo.toml b/compiler/rustc_codegen_llvm/Cargo.toml
index df4a9fea19d74..0ad39c24025fd 100644
--- a/compiler/rustc_codegen_llvm/Cargo.toml
+++ b/compiler/rustc_codegen_llvm/Cargo.toml
@@ -5,7 +5,6 @@ edition = "2021"
 
 [lib]
 test = false
-doctest = false
 
 [dependencies]
 bitflags = "1.0"
diff --git a/compiler/rustc_const_eval/Cargo.toml b/compiler/rustc_const_eval/Cargo.toml
index 32e8233a0415f..e09a6d1d6f5aa 100644
--- a/compiler/rustc_const_eval/Cargo.toml
+++ b/compiler/rustc_const_eval/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 tracing = "0.1"
diff --git a/compiler/rustc_const_eval/src/interpret/validity.rs b/compiler/rustc_const_eval/src/interpret/validity.rs
index 14aaee6ac3f9e..d4146c2424101 100644
--- a/compiler/rustc_const_eval/src/interpret/validity.rs
+++ b/compiler/rustc_const_eval/src/interpret/validity.rs
@@ -56,7 +56,7 @@ macro_rules! throw_validation_failure {
 /// This lets you use the patterns as a kind of validation list, asserting which errors
 /// can possibly happen:
 ///
-/// ```
+/// ```ignore(illustrative)
 /// let v = try_validation!(some_fn(), some_path, {
 ///     Foo | Bar | Baz => { "some failure" },
 /// });
@@ -65,7 +65,7 @@ macro_rules! throw_validation_failure {
 /// The patterns must be of type `UndefinedBehaviorInfo`.
 /// An additional expected parameter can also be added to the failure message:
 ///
-/// ```
+/// ```ignore(illustrative)
 /// let v = try_validation!(some_fn(), some_path, {
 ///     Foo | Bar | Baz => { "some failure" } expected { "something that wasn't a failure" },
 /// });
@@ -74,7 +74,7 @@ macro_rules! throw_validation_failure {
 /// An additional nicety is that both parameters actually take format args, so you can just write
 /// the format string in directly:
 ///
-/// ```
+/// ```ignore(illustrative)
 /// let v = try_validation!(some_fn(), some_path, {
 ///     Foo | Bar | Baz => { "{:?}", some_failure } expected { "{}", expected_value },
 /// });
diff --git a/compiler/rustc_data_structures/Cargo.toml b/compiler/rustc_data_structures/Cargo.toml
index 2d8658db5e6aa..9daa21ef6b11d 100644
--- a/compiler/rustc_data_structures/Cargo.toml
+++ b/compiler/rustc_data_structures/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 arrayvec = { version = "0.7", default-features = false }
diff --git a/compiler/rustc_error_messages/Cargo.toml b/compiler/rustc_error_messages/Cargo.toml
index fc84c7c8665b4..9945f337995d3 100644
--- a/compiler/rustc_error_messages/Cargo.toml
+++ b/compiler/rustc_error_messages/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 fluent-bundle = "0.15.2"
diff --git a/compiler/rustc_errors/Cargo.toml b/compiler/rustc_errors/Cargo.toml
index 1eb9dca2a2b91..7803a0792e12c 100644
--- a/compiler/rustc_errors/Cargo.toml
+++ b/compiler/rustc_errors/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 tracing = "0.1"
diff --git a/compiler/rustc_feature/Cargo.toml b/compiler/rustc_feature/Cargo.toml
index 3d8d0db20d122..6f6468646fc7c 100644
--- a/compiler/rustc_feature/Cargo.toml
+++ b/compiler/rustc_feature/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 rustc_data_structures = { path = "../rustc_data_structures" }
diff --git a/compiler/rustc_hir/Cargo.toml b/compiler/rustc_hir/Cargo.toml
index 69ad623b7ea86..129f8d235adbc 100644
--- a/compiler/rustc_hir/Cargo.toml
+++ b/compiler/rustc_hir/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 rustc_arena = { path = "../rustc_arena" }
diff --git a/compiler/rustc_hir_pretty/Cargo.toml b/compiler/rustc_hir_pretty/Cargo.toml
index 46a8e7deeed04..1ea7be1ae7b52 100644
--- a/compiler/rustc_hir_pretty/Cargo.toml
+++ b/compiler/rustc_hir_pretty/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 rustc_ast_pretty = { path = "../rustc_ast_pretty" }
diff --git a/compiler/rustc_incremental/Cargo.toml b/compiler/rustc_incremental/Cargo.toml
index d3c425a072bce..179e85f32c913 100644
--- a/compiler/rustc_incremental/Cargo.toml
+++ b/compiler/rustc_incremental/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 rustc_graphviz = { path = "../rustc_graphviz" }
diff --git a/compiler/rustc_index/Cargo.toml b/compiler/rustc_index/Cargo.toml
index 8a81a93a99cfd..d8ea5aa80b87a 100644
--- a/compiler/rustc_index/Cargo.toml
+++ b/compiler/rustc_index/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 arrayvec = { version = "0.7", default-features = false }
diff --git a/compiler/rustc_interface/Cargo.toml b/compiler/rustc_interface/Cargo.toml
index f3c38875b37c6..f0cb861c782f0 100644
--- a/compiler/rustc_interface/Cargo.toml
+++ b/compiler/rustc_interface/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 libloading = "0.7.1"
diff --git a/compiler/rustc_lexer/Cargo.toml b/compiler/rustc_lexer/Cargo.toml
index 35af110537d4c..ad685c2ad19f4 100644
--- a/compiler/rustc_lexer/Cargo.toml
+++ b/compiler/rustc_lexer/Cargo.toml
@@ -12,7 +12,6 @@ Rust lexer used by rustc. No stability guarantees are provided.
 # Note: do not remove this blank `[lib]` section.
 # This will be used when publishing this crate as `rustc-ap-rustc_lexer`.
 [lib]
-doctest = false
 
 # Note that this crate purposefully does not depend on other rustc crates
 [dependencies]
diff --git a/compiler/rustc_metadata/Cargo.toml b/compiler/rustc_metadata/Cargo.toml
index 2c5db9d8b2765..6d85103c9d132 100644
--- a/compiler/rustc_metadata/Cargo.toml
+++ b/compiler/rustc_metadata/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 libloading = "0.7.1"
diff --git a/compiler/rustc_mir_build/Cargo.toml b/compiler/rustc_mir_build/Cargo.toml
index 30f90e383a889..c726fa3a33fff 100644
--- a/compiler/rustc_mir_build/Cargo.toml
+++ b/compiler/rustc_mir_build/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 rustc_arena = { path = "../rustc_arena" }
diff --git a/compiler/rustc_mir_dataflow/Cargo.toml b/compiler/rustc_mir_dataflow/Cargo.toml
index 385e9ba748fb9..324644b67928e 100644
--- a/compiler/rustc_mir_dataflow/Cargo.toml
+++ b/compiler/rustc_mir_dataflow/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 polonius-engine = "0.13.0"
diff --git a/compiler/rustc_mir_transform/Cargo.toml b/compiler/rustc_mir_transform/Cargo.toml
index 85b7a4af59894..53545cff0cb34 100644
--- a/compiler/rustc_mir_transform/Cargo.toml
+++ b/compiler/rustc_mir_transform/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 itertools = "0.10.1"
diff --git a/compiler/rustc_mir_transform/src/coverage/test_macros/Cargo.toml b/compiler/rustc_mir_transform/src/coverage/test_macros/Cargo.toml
index f5e8b65656a3e..f753caa91248e 100644
--- a/compiler/rustc_mir_transform/src/coverage/test_macros/Cargo.toml
+++ b/compiler/rustc_mir_transform/src/coverage/test_macros/Cargo.toml
@@ -5,4 +5,3 @@ edition = "2021"
 
 [lib]
 proc-macro = true
-doctest = false
diff --git a/compiler/rustc_monomorphize/Cargo.toml b/compiler/rustc_monomorphize/Cargo.toml
index 59ca04ec868d1..6ee5330b63f51 100644
--- a/compiler/rustc_monomorphize/Cargo.toml
+++ b/compiler/rustc_monomorphize/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 smallvec = { version = "1.8.1", features = [ "union", "may_dangle" ] }
diff --git a/compiler/rustc_parse/Cargo.toml b/compiler/rustc_parse/Cargo.toml
index c6ca260e9831e..a5c94e1640334 100644
--- a/compiler/rustc_parse/Cargo.toml
+++ b/compiler/rustc_parse/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 bitflags = "1.0"
diff --git a/compiler/rustc_plugin_impl/Cargo.toml b/compiler/rustc_plugin_impl/Cargo.toml
index c409b6c3e5440..fa27bfc61d141 100644
--- a/compiler/rustc_plugin_impl/Cargo.toml
+++ b/compiler/rustc_plugin_impl/Cargo.toml
@@ -5,7 +5,6 @@ build = false
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 libloading = "0.7.1"
diff --git a/compiler/rustc_query_system/Cargo.toml b/compiler/rustc_query_system/Cargo.toml
index d7599a56c0b66..faddad7417109 100644
--- a/compiler/rustc_query_system/Cargo.toml
+++ b/compiler/rustc_query_system/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 parking_lot = "0.11"
diff --git a/compiler/rustc_resolve/Cargo.toml b/compiler/rustc_resolve/Cargo.toml
index 5d2b606b43cd5..d66db1d7a0dd5 100644
--- a/compiler/rustc_resolve/Cargo.toml
+++ b/compiler/rustc_resolve/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 bitflags = "1.2.1"
diff --git a/compiler/rustc_span/Cargo.toml b/compiler/rustc_span/Cargo.toml
index 7227b193f2194..48a2ab0f904ac 100644
--- a/compiler/rustc_span/Cargo.toml
+++ b/compiler/rustc_span/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 rustc_serialize = { path = "../rustc_serialize" }
diff --git a/compiler/rustc_symbol_mangling/Cargo.toml b/compiler/rustc_symbol_mangling/Cargo.toml
index 3db05225722e7..2a29ad6a9e56b 100644
--- a/compiler/rustc_symbol_mangling/Cargo.toml
+++ b/compiler/rustc_symbol_mangling/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 bitflags = "1.2.1"
diff --git a/compiler/rustc_trait_selection/Cargo.toml b/compiler/rustc_trait_selection/Cargo.toml
index 566f236f26a8c..67613e1a4ebc0 100644
--- a/compiler/rustc_trait_selection/Cargo.toml
+++ b/compiler/rustc_trait_selection/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 rustc_parse_format = { path = "../rustc_parse_format" }
diff --git a/compiler/rustc_type_ir/Cargo.toml b/compiler/rustc_type_ir/Cargo.toml
index 5aa3cf017fa68..c4008e9b61296 100644
--- a/compiler/rustc_type_ir/Cargo.toml
+++ b/compiler/rustc_type_ir/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 bitflags = "1.2.1"