rust-lang · xonx4l · Nov 7, 2025 · Nov 7, 2025 · Nov 7, 2025 · Nov 9, 2025
diff --git a/compiler/rustc_error_codes/src/error_codes/E0412.md b/compiler/rustc_error_codes/src/error_codes/E0412.md
@@ -1,64 +1,6 @@
-A used type name is not in scope.
+#### Note: this error code is no longer emitted by the compiler.
 
-Erroneous code examples:
+Unresolved types are now reported under the unified error code E0425
+("cannot find ... in this scope").
 
-```compile_fail,E0412
-impl Something {} // error: type name `Something` is not in scope
-
-// or:
-
-trait Foo {
-    fn bar(N); // error: type name `N` is not in scope
-}
-
-// or:
-
-fn foo(x: T) {} // type name `T` is not in scope
-```
-
-To fix this error, please verify you didn't misspell the type name, you did
-declare it or imported it into the scope. Examples:
-
-```
-struct Something;
-
-impl Something {} // ok!
-
-// or:
-
-trait Foo {
-    type N;
-
-    fn bar(_: Self::N); // ok!
-}
-
-// or:
-
-fn foo<T>(x: T) {} // ok!
-```
-
-Another case that causes this error is when a type is imported into a parent
-module. To fix this, you can follow the suggestion and use File directly or
-`use super::File;` which will import the types from the parent namespace. An
-example that causes this error is below:
-
-```compile_fail,E0412
-use std::fs::File;
-
-mod foo {
-    fn some_function(f: File) {}
-}
-```
-
-```
-use std::fs::File;
-
-mod foo {
-    // either
-    use super::File;
-    // or
-    // use std::fs::File;
-    fn foo(f: File) {}
-}
-# fn main() {} // don't insert it for us; that'll break imports
-```
+See the explanation for E0425 for guidance on common causes and fixes.
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
@@ -622,7 +622,7 @@ impl PathSource<'_, '_, '_> {
             (PathSource::Trait(_), true) => E0404,
             (PathSource::Trait(_), false) => E0405,
             (PathSource::Type | PathSource::DefineOpaques, true) => E0573,
-            (PathSource::Type | PathSource::DefineOpaques, false) => E0412,
+            (PathSource::Type | PathSource::DefineOpaques, false) => E0425,
             (PathSource::Struct(_), true) => E0574,
             (PathSource::Struct(_), false) => E0422,
             (PathSource::Expr(..), true) | (PathSource::Delegation, true) => E0423,
@@ -3161,7 +3161,7 @@ impl<'a, 'ast, 'ra, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
         result
     }
 
-    /// When evaluating a `trait` use its associated types' idents for suggestions in E0412.
+    /// When evaluating a `trait` use its associated types' idents for suggestions in E0425.
     fn resolve_trait_items(&mut self, trait_items: &'ast [Box<AssocItem>]) {
         let trait_assoc_items =
             replace(&mut self.diag_metadata.current_trait_assoc_items, Some(trait_items));
@@ -4362,15 +4362,15 @@ impl<'a, 'ast, 'ra, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
 
                 // There are two different error messages user might receive at
                 // this point:
-                // - E0412 cannot find type `{}` in this scope
+                // - E0425 cannot find `{}` in this scope
                 // - E0433 failed to resolve: use of undeclared type or module `{}`
                 //
                 // The first one is emitted for paths in type-position, and the
                 // latter one - for paths in expression-position.
                 //
                 // Thus (since we're in expression-position at this point), not to
                 // confuse the user, we want to keep the *message* from E0433 (so
-                // `parent_err`), but we want *hints* from E0412 (so `err`).
+                // `parent_err`), but we want *hints* from E0425 (so `err`).
                 //
                 // And that's what happens below - we're just mixing both messages
                 // into a single one.

diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -705,7 +705,7 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
             if !enum_candidates.is_empty() {
                 enum_candidates.sort();
 
-                // Contextualize for E0412 "cannot find type", but don't belabor the point
+                // Contextualize for E0425 "cannot find type", but don't belabor the point
                 // (that it's a variant) for E0573 "expected type, found variant".
                 let preamble = if res.is_none() {
                     let others = match enum_candidates.len() {
@@ -1127,7 +1127,7 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
                 }
 
                 self.suggest_ident_hidden_by_hygiene(err, path, span);
-            } else if err_code == E0412 {
+                // cannot find type in this scope
                 if let Some(correct) = Self::likely_rust_type(path) {
                     err.span_suggestion(
                         span,

diff --git a/src/tools/cargo b/src/tools/cargo
diff --git a/src/tools/clippy/tests/ui/crashes/ice-6252.stderr b/src/tools/clippy/tests/ui/crashes/ice-6252.stderr
@@ -1,4 +1,4 @@
-error[E0412]: cannot find type `PhantomData` in this scope
+error[E0425]: cannot find type `PhantomData` in this scope
   --> tests/ui/crashes/ice-6252.rs:9:9
    |
 LL |     _n: PhantomData,
@@ -9,7 +9,7 @@ help: consider importing this struct
 LL + use std::marker::PhantomData;
    |
 
-error[E0412]: cannot find type `VAL` in this scope
+error[E0425]: cannot find type `VAL` in this scope
   --> tests/ui/crashes/ice-6252.rs:12:63
    |
 LL | impl<N, M> TypeVal<usize> for Multiply<N, M> where N: TypeVal<VAL> {}
@@ -31,5 +31,5 @@ LL | impl<N, M> TypeVal<usize> for Multiply<N, M> where N: TypeVal<VAL> {}
 
 error: aborting due to 3 previous errors
 
-Some errors have detailed explanations: E0046, E0412.
+Some errors have detailed explanations: E0046, E0425.
 For more information about an error, try `rustc --explain E0046`.
diff --git a/tests/rustdoc-ui/impl-fn-nesting.stderr b/tests/rustdoc-ui/impl-fn-nesting.stderr
@@ -10,7 +10,7 @@ error[E0405]: cannot find trait `UnknownBound` in this scope
 LL | pub fn f<B: UnknownBound>(a: UnknownType, b: B) {
    |             ^^^^^^^^^^^^ not found in this scope
 
-error[E0412]: cannot find type `UnknownType` in this scope
+error[E0425]: cannot find type `UnknownType` in this scope
   --> $DIR/impl-fn-nesting.rs:11:30
    |
 LL | pub fn f<B: UnknownBound>(a: UnknownType, b: B) {
@@ -34,7 +34,7 @@ error[E0405]: cannot find trait `UnknownBound` in this scope
 LL |     impl<T: UnknownBound> UnknownTrait for T {}
    |             ^^^^^^^^^^^^ not found in this scope
 
-error[E0412]: cannot find type `UnknownType` in this scope
+error[E0425]: cannot find type `UnknownType` in this scope
   --> $DIR/impl-fn-nesting.rs:18:25
    |
 LL |     impl ValidTrait for UnknownType {}
@@ -46,19 +46,19 @@ error[E0405]: cannot find trait `UnknownBound` in this scope
 LL |     impl ValidTrait for ValidType where ValidTrait: UnknownBound {}
    |                                                     ^^^^^^^^^^^^ not found in this scope
 
-error[E0412]: cannot find type `UnknownType` in this scope
+error[E0425]: cannot find type `UnknownType` in this scope
   --> $DIR/impl-fn-nesting.rs:25:21
    |
 LL |         type Item = UnknownType;
    |                     ^^^^^^^^^^^ not found in this scope
 
-error[E0412]: cannot find type `UnknownType` in this scope
+error[E0425]: cannot find type `UnknownType` in this scope
   --> $DIR/impl-fn-nesting.rs:44:37
    |
 LL |             pub fn doubly_nested(c: UnknownType) {
    |                                     ^^^^^^^^^^^ not found in this scope
 
 error: aborting due to 10 previous errors
 
-Some errors have detailed explanations: E0405, E0412.
+Some errors have detailed explanations: E0405, E0425.
 For more information about an error, try `rustc --explain E0405`.
diff --git a/tests/ui/annotate-snippet/missing-type.stderr b/tests/ui/annotate-snippet/missing-type.stderr
@@ -1,4 +1,4 @@
-error[E0412]: cannot find type `Iter` in this scope
+error[E0425]: cannot find type `Iter` in this scope
   --> $DIR/missing-type.rs:4:12
    |
 LL |     let x: Iter;
@@ -18,4 +18,4 @@ LL + use std::collections::hash_map::Iter;
 
 error: aborting due to 1 previous error
 
-For more information about this error, try `rustc --explain E0412`.
+For more information about this error, try `rustc --explain E0425`.
diff --git a/tests/ui/argument-suggestions/extern-fn-arg-names.stderr b/tests/ui/argument-suggestions/extern-fn-arg-names.stderr
@@ -1,4 +1,4 @@
-error[E0412]: cannot find type `err` in this scope
+error[E0425]: cannot find type `err` in this scope
   --> $DIR/extern-fn-arg-names.rs:2:29
    |
 LL |     fn dstfn(src: i32, dst: err);
@@ -22,5 +22,5 @@ LL |     dstfn(1, /* dst */);
 
 error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0061, E0412.
+Some errors have detailed explanations: E0061, E0425.
 For more information about an error, try `rustc --explain E0061`.
diff --git a/tests/ui/argument-suggestions/issue-109831.rs b/tests/ui/argument-suggestions/issue-109831.rs
@@ -1,7 +1,7 @@
 struct A;
 struct B;
 
-fn f(b1: B, b2: B, a2: C) {} //~ ERROR E0412
+fn f(b1: B, b2: B, a2: C) {} //~ ERROR E0425
 
 fn main() {
     f(A, A, B, C); //~ ERROR E0425

diff --git a/tests/ui/argument-suggestions/issue-109831.stderr b/tests/ui/argument-suggestions/issue-109831.stderr
@@ -1,4 +1,4 @@
-error[E0412]: cannot find type `C` in this scope
+error[E0425]: cannot find type `C` in this scope
   --> $DIR/issue-109831.rs:4:24
    |
 LL | struct A;
@@ -48,5 +48,5 @@ LL +     f(/* B */, /* B */, B);
 
 error: aborting due to 3 previous errors
 
-Some errors have detailed explanations: E0061, E0412, E0425.
+Some errors have detailed explanations: E0061, E0425.
 For more information about an error, try `rustc --explain E0061`.
diff --git a/tests/ui/asm/issue-113788.rs b/tests/ui/asm/issue-113788.rs
@@ -2,6 +2,6 @@
 //@ needs-asm-support
 //@ only-x86_64
 fn main() {
-    let peb: *const PEB; //~ ERROR cannot find type `PEB` in this scope [E0412]
+    let peb: *const PEB; //~ ERROR cannot find type `PEB` in this scope [E0425]
     unsafe { std::arch::asm!("mov {0}, fs:[0x30]", out(reg) peb); }
 }
diff --git a/tests/ui/asm/issue-113788.stderr b/tests/ui/asm/issue-113788.stderr
@@ -1,9 +1,9 @@
-error[E0412]: cannot find type `PEB` in this scope
+error[E0425]: cannot find type `PEB` in this scope
   --> $DIR/issue-113788.rs:5:21
    |
 LL |     let peb: *const PEB;
    |                     ^^^ not found in this scope
 
 error: aborting due to 1 previous error
 
-For more information about this error, try `rustc --explain E0412`.
+For more information about this error, try `rustc --explain E0425`.
diff --git a/tests/ui/associated-consts/issue-93835.stderr b/tests/ui/associated-consts/issue-93835.stderr
@@ -4,7 +4,7 @@ error[E0425]: cannot find value `p` in this scope
 LL |     type_ascribe!(p, a<p:p<e=6>>);
    |                   ^ not found in this scope
 
-error[E0412]: cannot find type `a` in this scope
+error[E0425]: cannot find type `a` in this scope
   --> $DIR/issue-93835.rs:4:22
    |
 LL |     type_ascribe!(p, a<p:p<e=6>>);
@@ -39,5 +39,5 @@ LL |     type_ascribe!(p, a<p:p<e=6>>);
 
 error: aborting due to 5 previous errors
 
-Some errors have detailed explanations: E0405, E0412, E0425, E0658.
+Some errors have detailed explanations: E0405, E0425, E0658.
 For more information about an error, try `rustc --explain E0405`.
diff --git a/tests/ui/associated-type-bounds/return-type-notation/not-a-method.stderr b/tests/ui/associated-type-bounds/return-type-notation/not-a-method.stderr
@@ -16,7 +16,7 @@ error[E0576]: cannot find function `method` in this scope
 LL |     method(..): Send,
    |     ^^^^^^ not found in this scope
 
-error[E0412]: cannot find type `method` in this scope
+error[E0425]: cannot find type `method` in this scope
   --> $DIR/not-a-method.rs:36:5
    |
 LL |     method(): Send,
@@ -36,5 +36,5 @@ LL |     method(..): Send,
 
 error: aborting due to 6 previous errors
 
-Some errors have detailed explanations: E0412, E0573, E0575, E0576.
-For more information about an error, try `rustc --explain E0412`.
+Some errors have detailed explanations: E0425, E0573, E0575, E0576.
+For more information about an error, try `rustc --explain E0425`.
diff --git a/tests/ui/associated-types/associated-types-eq-1.stderr b/tests/ui/associated-types/associated-types-eq-1.stderr
@@ -1,4 +1,4 @@
-error[E0412]: cannot find type `A` in this scope
+error[E0425]: cannot find type `A` in this scope
   --> $DIR/associated-types-eq-1.rs:10:12
    |
 LL | fn foo2<I: Foo>(x: I) {
@@ -18,4 +18,4 @@ LL | fn foo2<I: Foo, A>(x: I) {
 
 error: aborting due to 1 previous error
 
-For more information about this error, try `rustc --explain E0412`.
+For more information about this error, try `rustc --explain E0425`.
diff --git a/tests/ui/async-await/in-trait/return-not-existing-pair.rs b/tests/ui/async-await/in-trait/return-not-existing-pair.rs
@@ -3,7 +3,7 @@
 
 trait MyTrait<'a, 'b, T> {
     async fn foo(&'a self, key: &'b T) -> (&'a ConnImpl, &'b T);
-    //~^ ERROR: cannot find type `ConnImpl` in this scope [E0412]
+    //~^ ERROR: cannot find type `ConnImpl` in this scope [E0425]
 }
 
 impl<'a, 'b, T, U> MyTrait<T> for U {

diff --git a/tests/ui/async-await/in-trait/return-not-existing-pair.stderr b/tests/ui/async-await/in-trait/return-not-existing-pair.stderr
@@ -9,7 +9,7 @@ help: indicate the anonymous lifetimes
 LL | impl<'a, 'b, T, U> MyTrait<'_, '_, T> for U {
    |                            +++++++
 
-error[E0412]: cannot find type `ConnImpl` in this scope
+error[E0425]: cannot find type `ConnImpl` in this scope
   --> $DIR/return-not-existing-pair.rs:5:48
    |
 LL |     async fn foo(&'a self, key: &'b T) -> (&'a ConnImpl, &'b T);
@@ -26,5 +26,5 @@ LL |     async fn foo(_: T) -> (&'a U, &'b T) {}
 
 error: aborting due to 3 previous errors
 
-Some errors have detailed explanations: E0308, E0412, E0726.
+Some errors have detailed explanations: E0308, E0425, E0726.
 For more information about an error, try `rustc --explain E0308`.
diff --git a/tests/ui/async-await/in-trait/return-not-existing-type-wrapping-rpitit.rs b/tests/ui/async-await/in-trait/return-not-existing-type-wrapping-rpitit.rs
@@ -5,7 +5,7 @@ struct Wrapper<T>(T);
 
 trait Foo {
     fn bar() -> Wrapper<Missing<impl Sized>>;
-    //~^ ERROR: cannot find type `Missing` in this scope [E0412]
+    //~^ ERROR: cannot find type `Missing` in this scope [E0425]
 }
 
 impl Foo for () {

diff --git a/tests/ui/async-await/in-trait/return-not-existing-type-wrapping-rpitit.stderr b/tests/ui/async-await/in-trait/return-not-existing-type-wrapping-rpitit.stderr
@@ -1,9 +1,9 @@
-error[E0412]: cannot find type `Missing` in this scope
+error[E0425]: cannot find type `Missing` in this scope
   --> $DIR/return-not-existing-type-wrapping-rpitit.rs:7:25
    |
 LL |     fn bar() -> Wrapper<Missing<impl Sized>>;
    |                         ^^^^^^^ not found in this scope
 
 error: aborting due to 1 previous error
 
-For more information about this error, try `rustc --explain E0412`.
+For more information about this error, try `rustc --explain E0425`.
diff --git a/tests/ui/async-await/issue-72590-type-error-sized.stderr b/tests/ui/async-await/issue-72590-type-error-sized.stderr
@@ -1,10 +1,10 @@
-error[E0412]: cannot find type `Nonexistent` in this scope
+error[E0425]: cannot find type `Nonexistent` in this scope
   --> $DIR/issue-72590-type-error-sized.rs:6:10
    |
 LL |     foo: Nonexistent,
    |          ^^^^^^^^^^^ not found in this scope
 
-error[E0412]: cannot find type `Missing` in this scope
+error[E0425]: cannot find type `Missing` in this scope
   --> $DIR/issue-72590-type-error-sized.rs:11:11
    |
 LL |     test: Missing
@@ -30,5 +30,5 @@ LL |     async fn frob(&self) {}
 
 error: aborting due to 3 previous errors
 
-Some errors have detailed explanations: E0277, E0412.
+Some errors have detailed explanations: E0277, E0425.
 For more information about an error, try `rustc --explain E0277`.
diff --git a/tests/ui/async-await/unconstrained-lifetimes.stderr b/tests/ui/async-await/unconstrained-lifetimes.stderr
@@ -1,9 +1,9 @@
-error[E0412]: cannot find type `Missing` in this scope
+error[E0425]: cannot find type `Missing` in this scope
   --> $DIR/unconstrained-lifetimes.rs:6:17
    |
 LL | async fn foo(_: Missing<'_>) {}
    |                 ^^^^^^^ not found in this scope
 
 error: aborting due to 1 previous error
 
-For more information about this error, try `rustc --explain E0412`.
+For more information about this error, try `rustc --explain E0425`.
diff --git a/tests/ui/borrowck/bad-drop-side-effects.stderr b/tests/ui/borrowck/bad-drop-side-effects.stderr
@@ -1,9 +1,9 @@
-error[E0412]: cannot find type `Missing` in this scope
+error[E0425]: cannot find type `Missing` in this scope
   --> $DIR/bad-drop-side-effects.rs:7:16
    |
 LL | impl<U> B for &Missing {
    |                ^^^^^^^ not found in this scope
 
 error: aborting due to 1 previous error
 
-For more information about this error, try `rustc --explain E0412`.
+For more information about this error, try `rustc --explain E0425`.
+1 −1		.github/workflows/main.yml
+483 −398		Cargo.lock
+34 −32		Cargo.toml
+2 −2		crates/cargo-test-macro/Cargo.toml
+2 −2		crates/cargo-test-support/Cargo.toml
+2 −2		crates/cargo-util-schemas/Cargo.toml
+2 −2		crates/cargo-util/Cargo.toml
+2 −2		crates/crates-io/Cargo.toml
+2 −2		credential/cargo-credential-libsecret/Cargo.toml
+2 −2		credential/cargo-credential-macos-keychain/Cargo.toml
+2 −2		credential/cargo-credential-wincred/Cargo.toml
+1 −0		src/bin/cargo/commands/build.rs
+1 −5		src/bin/cargo/commands/clean.rs
+0 −2		src/bin/cargo/commands/package.rs
+0 −2		src/bin/cargo/commands/publish.rs
+1 −6		src/bin/cargo/commands/tree.rs
+3 −39		src/bin/cargo/commands/uninstall.rs
+3 −0		src/cargo/core/compiler/build_config.rs
+160 −0		src/cargo/core/compiler/build_plan.rs
+4 −4		src/cargo/core/compiler/build_runner/compilation_files.rs
+23 −3		src/cargo/core/compiler/build_runner/mod.rs
+3 −3		src/cargo/core/compiler/compilation.rs
+1 −1		src/cargo/core/compiler/compile_kind.rs
+14 −2		src/cargo/core/compiler/custom_build.rs
+4 −22		src/cargo/core/compiler/fingerprint/dep_info.rs
+8 −529		src/cargo/core/compiler/fingerprint/dirty_reason.rs
+19 −74		src/cargo/core/compiler/fingerprint/mod.rs
+12 −9		src/cargo/core/compiler/job_queue/job_state.rs
+44 −40		src/cargo/core/compiler/job_queue/mod.rs
+6 −11		src/cargo/core/compiler/layout.rs
+95 −75		src/cargo/core/compiler/mod.rs
+3 −12		src/cargo/core/compiler/output_depinfo.rs
+6 −0		src/cargo/core/compiler/standard_lib.rs
+10 −0		src/cargo/core/compiler/unit.rs
+10 −10		src/cargo/core/package.rs
+1 −2		src/cargo/ops/cargo_compile/mod.rs
+0 −16		src/cargo/ops/cargo_install.rs
+1 −1		src/cargo/ops/cargo_package/vcs.rs
+2 −32		src/cargo/ops/common_for_install_and_uninstall.rs
+1 −1		src/cargo/ops/resolve.rs
+5 −5		src/cargo/sources/registry/remote.rs
+21 −74		src/cargo/util/command_prelude.rs
+0 −311		src/cargo/util/context/config_value.rs
+740 −59		src/cargo/util/context/mod.rs
+3 −3		src/cargo/util/context/path.rs
+0 −511		src/cargo/util/context/schema.rs
+5 −4		src/cargo/util/context/value.rs
+2 −2		src/cargo/util/flock.rs
+0 −8		src/cargo/util/log_message.rs
+1 −1		src/cargo/util/mod.rs
+0 −43		src/cargo/util/once.rs
+3 −5		src/cargo/util/toml/mod.rs
+1 −12		src/doc/contrib/src/implementation/console.md
+9 −0		src/doc/man/cargo-build.md
+10 −0		src/doc/man/generated_txt/cargo-build.txt
+9 −138		src/doc/src/CHANGELOG.md
+9 −0		src/doc/src/commands/cargo-build.md
+2 −2		src/doc/src/reference/build-scripts.md
+1 −1		src/doc/src/reference/environment-variables.md
+34 −19		src/doc/src/reference/unstable.md
+1 −0		src/etc/_cargo
+11 −0		src/etc/man/cargo-build.1
+44 −163		tests/testsuite/build_analysis.rs
+244 −0		tests/testsuite/build_plan.rs
+17 −15		tests/testsuite/cargo_build/help/stdout.term.svg
+2 −47		tests/testsuite/config.rs
+1 −1		tests/testsuite/config_include.rs
+0 −100		tests/testsuite/dep_info.rs
+0 −151		tests/testsuite/install.rs
+1 −0		tests/testsuite/main.rs
+121 −0		tests/testsuite/metabuild.rs
+0 −23		tests/testsuite/progress.rs
+0 −68		tests/testsuite/warning_override.rs