diff --git a/compiler/rustc_attr/src/builtin.rs b/compiler/rustc_attr/src/builtin.rs
index f013ff45a4fe5..76659458dad99 100644
--- a/compiler/rustc_attr/src/builtin.rs
+++ b/compiler/rustc_attr/src/builtin.rs
@@ -548,7 +548,11 @@ pub fn cfg_matches(
                     UNEXPECTED_CFGS,
                     cfg.span,
                     lint_node_id,
-                    "unexpected `cfg` condition value",
+                    if let Some(value) = cfg.value {
+                        format!("unexpected `cfg` condition value: `{value}`")
+                    } else {
+                        format!("unexpected `cfg` condition value: (none)")
+                    },
                     BuiltinLintDiagnostics::UnexpectedCfgValue(
                         (cfg.name, cfg.name_span),
                         cfg.value.map(|v| (v, cfg.value_span.unwrap())),
@@ -560,7 +564,7 @@ pub fn cfg_matches(
                     UNEXPECTED_CFGS,
                     cfg.span,
                     lint_node_id,
-                    "unexpected `cfg` condition name",
+                    format!("unexpected `cfg` condition name: `{}`", cfg.name),
                     BuiltinLintDiagnostics::UnexpectedCfgName(
                         (cfg.name, cfg.name_span),
                         cfg.value.map(|v| (v, cfg.value_span.unwrap())),
diff --git a/compiler/rustc_errors/src/diagnostic_builder.rs b/compiler/rustc_errors/src/diagnostic_builder.rs
index 5e23ae655fe80..85acf8ab5aaef 100644
--- a/compiler/rustc_errors/src/diagnostic_builder.rs
+++ b/compiler/rustc_errors/src/diagnostic_builder.rs
@@ -659,6 +659,7 @@ impl<'a, G: EmissionGuarantee> DiagnosticBuilder<'a, G> {
         msg: impl Into<SubdiagnosticMessage>,
     ) -> &mut Self);
     forward!(pub fn help(&mut self, msg: impl Into<SubdiagnosticMessage>) -> &mut Self);
+    forward!(pub fn help_once(&mut self, msg: impl Into<SubdiagnosticMessage>) -> &mut Self);
     forward!(pub fn span_help(
         &mut self,
         sp: impl Into<MultiSpan>,
diff --git a/compiler/rustc_lint/src/context.rs b/compiler/rustc_lint/src/context.rs
index 3c5cde4309b44..1ed9b86d66c96 100644
--- a/compiler/rustc_lint/src/context.rs
+++ b/compiler/rustc_lint/src/context.rs
@@ -727,11 +727,14 @@ pub trait LintContext: Sized {
                                 .collect::<Vec<_>>();
                             possibilities.sort();
 
+                            let mut should_print_possibilities = true;
                             if let Some((value, value_span)) = value {
                                 if best_match_values.contains(&Some(value)) {
                                     db.span_suggestion(name_span, "there is a config with a similar name and value", best_match, Applicability::MaybeIncorrect);
+                                    should_print_possibilities = false;
                                 } else if best_match_values.contains(&None) {
                                     db.span_suggestion(name_span.to(value_span), "there is a config with a similar name and no value", best_match, Applicability::MaybeIncorrect);
+                                    should_print_possibilities = false;
                                 } else if let Some(first_value) = possibilities.first() {
                                     db.span_suggestion(name_span.to(value_span), "there is a config with a similar name and different values", format!("{best_match} = \"{first_value}\""), Applicability::MaybeIncorrect);
                                 } else {
@@ -741,13 +744,25 @@ pub trait LintContext: Sized {
                                 db.span_suggestion(name_span, "there is a config with a similar name", best_match, Applicability::MaybeIncorrect);
                             }
 
-                            if !possibilities.is_empty() {
+                            if !possibilities.is_empty() && should_print_possibilities {
                                 let possibilities = possibilities.join("`, `");
                                 db.help(format!("expected values for `{best_match}` are: `{possibilities}`"));
                             }
                         } else {
                             db.span_suggestion(name_span, "there is a config with a similar name", best_match, Applicability::MaybeIncorrect);
                         }
+                    } else if !possibilities.is_empty() {
+                        let mut possibilities = possibilities.iter()
+                            .map(Symbol::as_str)
+                            .collect::<Vec<_>>();
+                        possibilities.sort();
+                        let possibilities = possibilities.join("`, `");
+
+                        // The list of expected names can be long (even by default) and
+                        // so the diagnostic produced can take a lot of space. To avoid
+                        // cloging the user output we only want to print that diagnostic
+                        // once.
+                        db.help_once(format!("expected names are: `{possibilities}`"));
                     }
                 },
                 BuiltinLintDiagnostics::UnexpectedCfgValue((name, name_span), value) => {
diff --git a/tests/rustdoc-ui/check-cfg/check-cfg.stderr b/tests/rustdoc-ui/check-cfg/check-cfg.stderr
index 03fb6f96fb5f9..d010c1f7ec627 100644
--- a/tests/rustdoc-ui/check-cfg/check-cfg.stderr
+++ b/tests/rustdoc-ui/check-cfg/check-cfg.stderr
@@ -1,4 +1,4 @@
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `uniz`
   --> $DIR/check-cfg.rs:5:7
    |
 LL | #[cfg(uniz)]
diff --git a/tests/rustdoc-ui/doctest/check-cfg-test.stderr b/tests/rustdoc-ui/doctest/check-cfg-test.stderr
index f84543c207254..0bfd569e381eb 100644
--- a/tests/rustdoc-ui/doctest/check-cfg-test.stderr
+++ b/tests/rustdoc-ui/doctest/check-cfg-test.stderr
@@ -1,4 +1,4 @@
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `invalid`
   --> $DIR/check-cfg-test.rs:9:7
    |
 LL | #[cfg(feature = "invalid")]
diff --git a/tests/ui/check-cfg/allow-same-level.stderr b/tests/ui/check-cfg/allow-same-level.stderr
index 7797de584b9e1..b0c459fabf8eb 100644
--- a/tests/ui/check-cfg/allow-same-level.stderr
+++ b/tests/ui/check-cfg/allow-same-level.stderr
@@ -1,9 +1,10 @@
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `FALSE`
   --> $DIR/allow-same-level.rs:7:7
    |
 LL | #[cfg(FALSE)]
    |       ^^^^^
    |
+   = help: expected names are: `debug_assertions`, `doc`, `doctest`, `feature`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `sanitize`, `target_abi`, `target_arch`, `target_endian`, `target_env`, `target_family`, `target_feature`, `target_has_atomic`, `target_has_atomic_equal_alignment`, `target_has_atomic_load_store`, `target_os`, `target_pointer_width`, `target_thread_local`, `target_vendor`, `test`, `unix`, `windows`
    = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: 1 warning emitted
diff --git a/tests/ui/check-cfg/compact-names.stderr b/tests/ui/check-cfg/compact-names.stderr
index f1fc4285a71b7..b0228774b751b 100644
--- a/tests/ui/check-cfg/compact-names.stderr
+++ b/tests/ui/check-cfg/compact-names.stderr
@@ -1,9 +1,10 @@
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `target_architecture`
   --> $DIR/compact-names.rs:11:28
    |
 LL | #[cfg(target(os = "linux", architecture = "arm"))]
    |                            ^^^^^^^^^^^^^^^^^^^^
    |
+   = help: expected names are: `debug_assertions`, `doc`, `doctest`, `feature`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `sanitize`, `target_abi`, `target_arch`, `target_endian`, `target_env`, `target_family`, `target_feature`, `target_has_atomic`, `target_has_atomic_equal_alignment`, `target_has_atomic_load_store`, `target_os`, `target_pointer_width`, `target_thread_local`, `target_vendor`, `test`, `unix`, `windows`
    = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: 1 warning emitted
diff --git a/tests/ui/check-cfg/compact-values.stderr b/tests/ui/check-cfg/compact-values.stderr
index b7269a652eaa7..bb2f4915b5ef6 100644
--- a/tests/ui/check-cfg/compact-values.stderr
+++ b/tests/ui/check-cfg/compact-values.stderr
@@ -1,4 +1,4 @@
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `X`
   --> $DIR/compact-values.rs:11:28
    |
 LL | #[cfg(target(os = "linux", arch = "X"))]
diff --git a/tests/ui/check-cfg/diagnotics.stderr b/tests/ui/check-cfg/diagnotics.stderr
index 8b9fef09d09ec..31c0db03a7e0f 100644
--- a/tests/ui/check-cfg/diagnotics.stderr
+++ b/tests/ui/check-cfg/diagnotics.stderr
@@ -1,4 +1,4 @@
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `featur`
   --> $DIR/diagnotics.rs:4:7
    |
 LL | #[cfg(featur)]
@@ -7,19 +7,18 @@ LL | #[cfg(featur)]
    = help: expected values for `feature` are: `foo`
    = note: `#[warn(unexpected_cfgs)]` on by default
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `featur`
   --> $DIR/diagnotics.rs:8:7
    |
 LL | #[cfg(featur = "foo")]
    |       ^^^^^^^^^^^^^^
    |
-   = help: expected values for `feature` are: `foo`
 help: there is a config with a similar name and value
    |
 LL | #[cfg(feature = "foo")]
    |       ~~~~~~~
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `featur`
   --> $DIR/diagnotics.rs:12:7
    |
 LL | #[cfg(featur = "fo")]
@@ -31,13 +30,13 @@ help: there is a config with a similar name and different values
 LL | #[cfg(feature = "foo")]
    |       ~~~~~~~~~~~~~~~
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `no_value`
   --> $DIR/diagnotics.rs:19:7
    |
 LL | #[cfg(no_value)]
    |       ^^^^^^^^ help: there is a config with a similar name: `no_values`
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `no_value`
   --> $DIR/diagnotics.rs:23:7
    |
 LL | #[cfg(no_value = "foo")]
@@ -48,7 +47,7 @@ help: there is a config with a similar name and no value
 LL | #[cfg(no_values)]
    |       ~~~~~~~~~
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `bar`
   --> $DIR/diagnotics.rs:27:7
    |
 LL | #[cfg(no_values = "bar")]
diff --git a/tests/ui/check-cfg/empty-names.stderr b/tests/ui/check-cfg/empty-names.stderr
index f926d1133cced..9bba852c6defd 100644
--- a/tests/ui/check-cfg/empty-names.stderr
+++ b/tests/ui/check-cfg/empty-names.stderr
@@ -1,9 +1,10 @@
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `unknown_key`
   --> $DIR/empty-names.rs:6:7
    |
 LL | #[cfg(unknown_key = "value")]
    |       ^^^^^^^^^^^^^^^^^^^^^
    |
+   = help: expected names are: `debug_assertions`, `doc`, `doctest`, `feature`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `sanitize`, `target_abi`, `target_arch`, `target_endian`, `target_env`, `target_family`, `target_feature`, `target_has_atomic`, `target_has_atomic_equal_alignment`, `target_has_atomic_load_store`, `target_os`, `target_pointer_width`, `target_thread_local`, `target_vendor`, `test`, `unix`, `windows`
    = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: 1 warning emitted
diff --git a/tests/ui/check-cfg/empty-values.stderr b/tests/ui/check-cfg/empty-values.stderr
index a0168b2caa8e3..932651c5bfe17 100644
--- a/tests/ui/check-cfg/empty-values.stderr
+++ b/tests/ui/check-cfg/empty-values.stderr
@@ -1,4 +1,4 @@
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `value`
   --> $DIR/empty-values.rs:6:7
    |
 LL | #[cfg(test = "value")]
diff --git a/tests/ui/check-cfg/invalid-cfg-name.stderr b/tests/ui/check-cfg/invalid-cfg-name.stderr
index ed09f8cb66d29..8c3c72c96671f 100644
--- a/tests/ui/check-cfg/invalid-cfg-name.stderr
+++ b/tests/ui/check-cfg/invalid-cfg-name.stderr
@@ -1,4 +1,4 @@
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `widnows`
   --> $DIR/invalid-cfg-name.rs:7:7
    |
 LL | #[cfg(widnows)]
diff --git a/tests/ui/check-cfg/invalid-cfg-value.stderr b/tests/ui/check-cfg/invalid-cfg-value.stderr
index 776d264a7adcb..947beac6ffd6e 100644
--- a/tests/ui/check-cfg/invalid-cfg-value.stderr
+++ b/tests/ui/check-cfg/invalid-cfg-value.stderr
@@ -1,4 +1,4 @@
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `sedre`
   --> $DIR/invalid-cfg-value.rs:7:7
    |
 LL | #[cfg(feature = "sedre")]
@@ -9,7 +9,7 @@ LL | #[cfg(feature = "sedre")]
    = note: expected values for `feature` are: `full`, `serde`
    = note: `#[warn(unexpected_cfgs)]` on by default
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `rand`
   --> $DIR/invalid-cfg-value.rs:14:7
    |
 LL | #[cfg(feature = "rand")]
diff --git a/tests/ui/check-cfg/mix.stderr b/tests/ui/check-cfg/mix.stderr
index 07c514aed5242..23da9f22a72c7 100644
--- a/tests/ui/check-cfg/mix.stderr
+++ b/tests/ui/check-cfg/mix.stderr
@@ -1,4 +1,4 @@
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `widnows`
   --> $DIR/mix.rs:11:7
    |
 LL | #[cfg(widnows)]
@@ -6,7 +6,7 @@ LL | #[cfg(widnows)]
    |
    = note: `#[warn(unexpected_cfgs)]` on by default
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: (none)
   --> $DIR/mix.rs:15:7
    |
 LL | #[cfg(feature)]
@@ -14,7 +14,7 @@ LL | #[cfg(feature)]
    |
    = note: expected values for `feature` are: `foo`
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `bar`
   --> $DIR/mix.rs:22:7
    |
 LL | #[cfg(feature = "bar")]
@@ -22,7 +22,7 @@ LL | #[cfg(feature = "bar")]
    |
    = note: expected values for `feature` are: `foo`
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `zebra`
   --> $DIR/mix.rs:26:7
    |
 LL | #[cfg(feature = "zebra")]
@@ -30,11 +30,13 @@ LL | #[cfg(feature = "zebra")]
    |
    = note: expected values for `feature` are: `foo`
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `uu`
   --> $DIR/mix.rs:30:12
    |
 LL | #[cfg_attr(uu, test)]
    |            ^^
+   |
+   = help: expected names are: `debug_assertions`, `doc`, `doctest`, `feature`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `sanitize`, `target_abi`, `target_arch`, `target_endian`, `target_env`, `target_family`, `target_feature`, `target_has_atomic`, `target_has_atomic_equal_alignment`, `target_has_atomic_load_store`, `target_os`, `target_pointer_width`, `target_thread_local`, `target_vendor`, `test`, `unix`, `windows`
 
 warning: unexpected condition value `bar` for condition name `feature`
    |
@@ -44,13 +46,13 @@ warning: unexpected `unknown_name` as condition name
    |
    = help: was set with `--cfg` but isn't in the `--check-cfg` expected names
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `widnows`
   --> $DIR/mix.rs:39:10
    |
 LL |     cfg!(widnows);
    |          ^^^^^^^ help: there is a config with a similar name: `windows`
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `bar`
   --> $DIR/mix.rs:42:10
    |
 LL |     cfg!(feature = "bar");
@@ -58,7 +60,7 @@ LL |     cfg!(feature = "bar");
    |
    = note: expected values for `feature` are: `foo`
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `zebra`
   --> $DIR/mix.rs:44:10
    |
 LL |     cfg!(feature = "zebra");
@@ -66,25 +68,25 @@ LL |     cfg!(feature = "zebra");
    |
    = note: expected values for `feature` are: `foo`
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `xxx`
   --> $DIR/mix.rs:46:10
    |
 LL |     cfg!(xxx = "foo");
    |          ^^^^^^^^^^^
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `xxx`
   --> $DIR/mix.rs:48:10
    |
 LL |     cfg!(xxx);
    |          ^^^
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `xxx`
   --> $DIR/mix.rs:50:14
    |
 LL |     cfg!(any(xxx, windows));
    |              ^^^
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `bad`
   --> $DIR/mix.rs:52:14
    |
 LL |     cfg!(any(feature = "bad", windows));
@@ -92,43 +94,43 @@ LL |     cfg!(any(feature = "bad", windows));
    |
    = note: expected values for `feature` are: `foo`
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `xxx`
   --> $DIR/mix.rs:54:23
    |
 LL |     cfg!(any(windows, xxx));
    |                       ^^^
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `xxx`
   --> $DIR/mix.rs:56:20
    |
 LL |     cfg!(all(unix, xxx));
    |                    ^^^
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `aa`
   --> $DIR/mix.rs:58:14
    |
 LL |     cfg!(all(aa, bb));
    |              ^^
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `bb`
   --> $DIR/mix.rs:58:18
    |
 LL |     cfg!(all(aa, bb));
    |                  ^^
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `aa`
   --> $DIR/mix.rs:61:14
    |
 LL |     cfg!(any(aa, bb));
    |              ^^
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `bb`
   --> $DIR/mix.rs:61:18
    |
 LL |     cfg!(any(aa, bb));
    |                  ^^
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `zebra`
   --> $DIR/mix.rs:64:20
    |
 LL |     cfg!(any(unix, feature = "zebra"));
@@ -136,13 +138,13 @@ LL |     cfg!(any(unix, feature = "zebra"));
    |
    = note: expected values for `feature` are: `foo`
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `xxx`
   --> $DIR/mix.rs:66:14
    |
 LL |     cfg!(any(xxx, feature = "zebra"));
    |              ^^^
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `zebra`
   --> $DIR/mix.rs:66:19
    |
 LL |     cfg!(any(xxx, feature = "zebra"));
@@ -150,19 +152,19 @@ LL |     cfg!(any(xxx, feature = "zebra"));
    |
    = note: expected values for `feature` are: `foo`
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `xxx`
   --> $DIR/mix.rs:69:14
    |
 LL |     cfg!(any(xxx, unix, xxx));
    |              ^^^
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `xxx`
   --> $DIR/mix.rs:69:25
    |
 LL |     cfg!(any(xxx, unix, xxx));
    |                         ^^^
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `zebra`
   --> $DIR/mix.rs:72:14
    |
 LL |     cfg!(all(feature = "zebra", feature = "zebra", feature = "zebra"));
@@ -170,7 +172,7 @@ LL |     cfg!(all(feature = "zebra", feature = "zebra", feature = "zebra"));
    |
    = note: expected values for `feature` are: `foo`
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `zebra`
   --> $DIR/mix.rs:72:33
    |
 LL |     cfg!(all(feature = "zebra", feature = "zebra", feature = "zebra"));
@@ -178,7 +180,7 @@ LL |     cfg!(all(feature = "zebra", feature = "zebra", feature = "zebra"));
    |
    = note: expected values for `feature` are: `foo`
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `zebra`
   --> $DIR/mix.rs:72:52
    |
 LL |     cfg!(all(feature = "zebra", feature = "zebra", feature = "zebra"));
diff --git a/tests/ui/check-cfg/no-values.stderr b/tests/ui/check-cfg/no-values.stderr
index ffa87dc58f203..b05a569dd01cd 100644
--- a/tests/ui/check-cfg/no-values.stderr
+++ b/tests/ui/check-cfg/no-values.stderr
@@ -1,4 +1,4 @@
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `foo`
   --> $DIR/no-values.rs:6:7
    |
 LL | #[cfg(feature = "foo")]
@@ -9,7 +9,7 @@ LL | #[cfg(feature = "foo")]
    = note: no expected value for `feature`
    = note: `#[warn(unexpected_cfgs)]` on by default
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `foo`
   --> $DIR/no-values.rs:10:7
    |
 LL | #[cfg(test = "foo")]
diff --git a/tests/ui/check-cfg/order-independant.names_after.stderr b/tests/ui/check-cfg/order-independant.names_after.stderr
index 91b81428b38a4..a308358e48587 100644
--- a/tests/ui/check-cfg/order-independant.names_after.stderr
+++ b/tests/ui/check-cfg/order-independant.names_after.stderr
@@ -1,4 +1,4 @@
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: (none)
   --> $DIR/order-independant.rs:8:7
    |
 LL | #[cfg(a)]
@@ -7,7 +7,7 @@ LL | #[cfg(a)]
    = note: expected values for `a` are: `b`
    = note: `#[warn(unexpected_cfgs)]` on by default
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `unk`
   --> $DIR/order-independant.rs:12:7
    |
 LL | #[cfg(a = "unk")]
diff --git a/tests/ui/check-cfg/order-independant.names_before.stderr b/tests/ui/check-cfg/order-independant.names_before.stderr
index 91b81428b38a4..a308358e48587 100644
--- a/tests/ui/check-cfg/order-independant.names_before.stderr
+++ b/tests/ui/check-cfg/order-independant.names_before.stderr
@@ -1,4 +1,4 @@
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: (none)
   --> $DIR/order-independant.rs:8:7
    |
 LL | #[cfg(a)]
@@ -7,7 +7,7 @@ LL | #[cfg(a)]
    = note: expected values for `a` are: `b`
    = note: `#[warn(unexpected_cfgs)]` on by default
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `unk`
   --> $DIR/order-independant.rs:12:7
    |
 LL | #[cfg(a = "unk")]
diff --git a/tests/ui/check-cfg/stmt-no-ice.stderr b/tests/ui/check-cfg/stmt-no-ice.stderr
index da65b596911d2..900ea4e4da06c 100644
--- a/tests/ui/check-cfg/stmt-no-ice.stderr
+++ b/tests/ui/check-cfg/stmt-no-ice.stderr
@@ -1,9 +1,10 @@
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `crossbeam_loom`
   --> $DIR/stmt-no-ice.rs:7:11
    |
 LL |     #[cfg(crossbeam_loom)]
    |           ^^^^^^^^^^^^^^
    |
+   = help: expected names are: `debug_assertions`, `doc`, `doctest`, `feature`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `sanitize`, `target_abi`, `target_arch`, `target_endian`, `target_env`, `target_family`, `target_feature`, `target_has_atomic`, `target_has_atomic_equal_alignment`, `target_has_atomic_load_store`, `target_os`, `target_pointer_width`, `target_thread_local`, `target_vendor`, `test`, `unix`, `windows`
    = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: 1 warning emitted
diff --git a/tests/ui/check-cfg/values-target-json.stderr b/tests/ui/check-cfg/values-target-json.stderr
index c705152d9fc66..e71149f337f58 100644
--- a/tests/ui/check-cfg/values-target-json.stderr
+++ b/tests/ui/check-cfg/values-target-json.stderr
@@ -1,4 +1,4 @@
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `linuz`
   --> $DIR/values-target-json.rs:13:7
    |
 LL | #[cfg(target_os = "linuz")]
diff --git a/tests/ui/check-cfg/well-known-names.stderr b/tests/ui/check-cfg/well-known-names.stderr
index 34c5d6172d94d..a5d38a99eeec9 100644
--- a/tests/ui/check-cfg/well-known-names.stderr
+++ b/tests/ui/check-cfg/well-known-names.stderr
@@ -1,4 +1,4 @@
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `target_oz`
   --> $DIR/well-known-names.rs:6:7
    |
 LL | #[cfg(target_oz = "linux")]
@@ -8,7 +8,7 @@ LL | #[cfg(target_oz = "linux")]
    |
    = note: `#[warn(unexpected_cfgs)]` on by default
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `features`
   --> $DIR/well-known-names.rs:13:7
    |
 LL | #[cfg(features = "foo")]
@@ -16,7 +16,7 @@ LL | #[cfg(features = "foo")]
    |       |
    |       help: there is a config with a similar name: `feature`
 
-warning: unexpected `cfg` condition name
+warning: unexpected `cfg` condition name: `uniw`
   --> $DIR/well-known-names.rs:20:7
    |
 LL | #[cfg(uniw)]
diff --git a/tests/ui/check-cfg/well-known-values.stderr b/tests/ui/check-cfg/well-known-values.stderr
index b381f5a4a0a15..6877d8f5bb727 100644
--- a/tests/ui/check-cfg/well-known-values.stderr
+++ b/tests/ui/check-cfg/well-known-values.stderr
@@ -1,4 +1,4 @@
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `linuz`
   --> $DIR/well-known-values.rs:7:7
    |
 LL | #[cfg(target_os = "linuz")]
@@ -9,7 +9,7 @@ LL | #[cfg(target_os = "linuz")]
    = note: expected values for `target_os` are: `aix`, `android`, `cuda`, `dragonfly`, `emscripten`, `espidf`, `freebsd`, `fuchsia`, `haiku`, `hermit`, `horizon`, `hurd`, `illumos`, `ios`, `l4re`, `linux`, `macos`, `netbsd`, `none`, `nto`, `openbsd`, `psp`, `redox`, `solaris`, `solid_asp3`, `teeos`, `tvos`, `uefi`, `unknown`, `vita`, `vxworks`, `wasi`, `watchos`, `windows`, `xous`
    = note: `#[warn(unexpected_cfgs)]` on by default
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `0`
   --> $DIR/well-known-values.rs:14:7
    |
 LL | #[cfg(target_has_atomic = "0")]
@@ -19,7 +19,7 @@ LL | #[cfg(target_has_atomic = "0")]
    |
    = note: expected values for `target_has_atomic` are: (none), `128`, `16`, `32`, `64`, `8`, `ptr`
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `aa`
   --> $DIR/well-known-values.rs:21:7
    |
 LL | #[cfg(unix = "aa")]
@@ -29,7 +29,7 @@ LL | #[cfg(unix = "aa")]
    |
    = note: no expected value for `unix`
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `miri`
   --> $DIR/well-known-values.rs:28:7
    |
 LL | #[cfg(miri = "miri")]
@@ -39,7 +39,7 @@ LL | #[cfg(miri = "miri")]
    |
    = note: no expected value for `miri`
 
-warning: unexpected `cfg` condition value
+warning: unexpected `cfg` condition value: `linux`
   --> $DIR/well-known-values.rs:35:7
    |
 LL | #[cfg(doc = "linux")]