delegation: supporting fair resolution for delegations to inherent impls by aerooneqq · Pull Request #162190 · rust-lang/rust

aerooneqq · 2026-09-02T12:28:54Z

petrochenkov · 2026-09-02T12:31:59Z

…n, r=<try> delegation: supporting fair resolution for delegations to inherent impls

rust-bors · 2026-09-02T13:37:14Z

☀️ Try build successful (CI)
Build commit: 8ac1108 (8ac1108b19e786f841079b426195f37c7b06487f)
Base parent: 3a43cb6 (3a43cb66f97d08ccde87a00599fac2d3c50eb177)

rust-timer · 2026-09-02T14:21:15Z

Finished benchmarking commit (8ac1108): comparison URL.

Overall result: ❌✅ regressions and improvements - please read:

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

Next, please: If you can, justify the regressions found in this try perf run in writing along with @rustbot label: +perf-regression-triaged. If not, fix the regressions and do another perf run. Neutral or positive results will clear the label automatically.

@bors rollup=never rustc-perf
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	0.2%	[0.1%, 0.3%]	43
Regressions ❌ (secondary)	0.2%	[0.1%, 0.4%]	30
Improvements ✅ (primary)	-0.8%	[-1.1%, -0.2%]	5
Improvements ✅ (secondary)	-0.5%	[-1.0%, -0.1%]	22
All ❌✅ (primary)	0.1%	[-1.1%, 0.3%]	48

Max RSS (memory usage)

Results (primary 9.2%, secondary 9.4%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	9.2%	[2.4%, 25.2%]	258
Regressions ❌ (secondary)	9.4%	[1.6%, 34.0%]	207
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	9.2%	[2.4%, 25.2%]	258

Cycles

Results (primary 2.5%, secondary 1.1%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	2.5%	[2.5%, 2.5%]	1
Regressions ❌ (secondary)	3.0%	[2.2%, 3.8%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.8%	[-2.8%, -2.8%]	1
All ❌✅ (primary)	2.5%	[2.5%, 2.5%]	1

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: missing data
Artifact size: 400.76 MiB -> 400.68 MiB (-0.02%)

rust-log-analyzer · 2026-09-02T14:34:09Z

The job aarch64-gnu-llvm-21-1 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

---- [ui] tests/ui/delegation/inherent-impls-enums.rs stdout ----

error: Error: expected failure status (Some(1)) but received status Some(101).
status: exit status: 101
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/delegation/inherent-impls-enums.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2" "--target=aarch64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/delegation/inherent-impls-enums" "-Znext-solver=coherence" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/aarch64-unknown-linux-gnu/native/rust-test-helpers"
stdout: none
--- stderr -------------------------------
error[E0308]: mismatched types
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-enums.rs:35:32
   |
LL | trait Trait<'a, AA, BB>
   | ----------------------- found this type parameter
...
LL |     reuse S::<'static, (), 1>::foo_self::<'static, _, _> as foo_self_4;
   |                                ^^^^^^^^
   |                                |
   |                                expected `S<'_, (), 1>`, found type parameter `Self`
   |                                arguments to this function are incorrect
   |
   = note:        expected enum `S<'_, (), 1>`
           found type parameter `Self`
note: method defined here
  --> /checkout/tests/ui/delegation/inherent-impls-enums.rs:10:8
   |
LL |     fn foo_self<'d: 'd, 'e, T, const B: bool>(self) {}
   |        ^^^^^^^^                               ----

error[E0284]: type annotations needed
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-enums.rs:44:32
   |
LL |     reuse S::<'static, (), 1>::foo_static::<'static, _, _> as foo_static_4;
   |                                ^^^^^^^^^^ cannot infer the value of const parameter `B` declared on the associated function `foo_static`
   |
note: required by a const generic parameter in `S::<'a, A, C>::foo_static`
  --> /checkout/tests/ui/delegation/inherent-impls-enums.rs:9:34
   |
LL |     fn foo_static<'d: 'd, 'e, T, const B: bool>() {}
   |                                  ^^^^^^^^^^^^^ required by this const generic parameter in `S::<'a, A, C>::foo_static`

error[E0308]: mismatched types
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-enums.rs:49:32
   |
LL |     reuse S::<'static, (), 1>::foo_self::<'static, _, _> as foo_self_4;
   |                                ^^^^^^^^
   |                                |
   |                                expected `S<'_, (), 1>`, found `X`
   |                                arguments to this function are incorrect
   |
   = note: expected enum `S<'_, (), 1>`
            found struct `X`
note: method defined here
  --> /checkout/tests/ui/delegation/inherent-impls-enums.rs:10:8
   |
LL |     fn foo_self<'d: 'd, 'e, T, const B: bool>(self) {}
   |        ^^^^^^^^                               ----

error[E0308]: mismatched types
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-enums.rs:64:32
   |
LL |     reuse S::<'static, (), 1>::foo_self::<'static, _, _> as foo_self_4;
   |                                ^^^^^^^^
   |                                |
   |                                expected `S<'_, (), 1>`, found `X`
   |                                arguments to this function are incorrect
   |
   = note: expected enum `S<'_, (), 1>`
            found struct `X`
note: method defined here
  --> /checkout/tests/ui/delegation/inherent-impls-enums.rs:10:8
   |
LL |     fn foo_self<'d: 'd, 'e, T, const B: bool>(self) {}
   |        ^^^^^^^^                               ----

##[error]error: internal compiler error: compiler/rustc_hir_typeck/src/lib.rs:127:9: can't type-check body of DefId(0:38 ~ inherent_impls_enums[170d]::foo_self_1::{constant#0})


thread 'rustc' (63753) panicked at compiler/rustc_hir_typeck/src/lib.rs:127:9:
Box<dyn Any>
stack backtrace:
   0: std::panicking::begin_panic::<rustc_errors::ExplicitBug>
   1: <rustc_errors::diagnostic::BugAbort as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
   2: <rustc_errors::DiagCtxtHandle>::span_bug::<rustc_span::span_encoding::Span, alloc::string::String>
   3: rustc_middle::util::bug::opt_span_bug_fmt::<rustc_span::span_encoding::Span>::{closure#0}
   4: rustc_middle::ty::context::tls::with_opt::<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}
   5: rustc_middle::ty::context::tls::with_context_opt::<rustc_middle::ty::context::tls::with_opt<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
   6: rustc_middle::util::bug::span_bug_fmt::<rustc_span::span_encoding::Span>
   7: rustc_hir_typeck::typeck_with_inspect::{closure#0}::{closure#0}
---
  11: rustc_hir_analysis::check_unused::check_unused_traits
      [... omitted 2 frames ...]
  12: rustc_hir_analysis::check_crate
  13: rustc_interface::passes::analysis
      [... omitted 2 frames ...]
  14: std::panicking::catch_unwind::<core::option::Option<rustc_interface::queries::Linker>, core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#1}>::{closure#2}::{closure#0}>>
  15: <std::thread::local::LocalKey<core::cell::Cell<*const ()>>>::with::<rustc_middle::ty::context::tls::enter_context<<rustc_middle::ty::context::GlobalCtxt>::enter<rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#1}>::{closure#2}, core::option::Option<rustc_interface::queries::Linker>>::{closure#1}, core::option::Option<rustc_interface::queries::Linker>>::{closure#0}, core::option::Option<rustc_interface::queries::Linker>>
  16: <rustc_middle::ty::context::TyCtxt>::create_global_ctxt::<core::option::Option<rustc_interface::queries::Linker>, rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#1}>::{closure#2}>
  17: rustc_interface::passes::create_and_enter_global_ctxt::<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#1}>
  18: std::panicking::catch_unwind::<(), core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#2}::{closure#0}>>
  19: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#2}
  20: rustc_span::create_session_globals_then::<(), rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#2}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}::{closure#0}>
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: please make sure that you have updated to the latest nightly

note: rustc 1.100.0-nightly (a5ce51d0a 2026-09-02) running on aarch64-unknown-linux-gnu

note: compiler flags: -Z simulate-remapped-rust-src-base=/rustc/FAKE_PREFIX -Z translate-remapped-path-to-local-path=no -Z ignore-directory-in-diagnostics-source-blocks=/cargo -Z ignore-directory-in-diagnostics-source-blocks=/checkout/vendor -C codegen-units=1 -Z ui-testing -Z deduplicate-diagnostics=no -Z write-long-types-to-disk=no -C strip=debuginfo -C prefer-dynamic -Z next-solver=coherence -C rpath -C debuginfo=0

query stack during panic:
#0 [typeck_root] type-checking `foo_self_1::{constant#0}`
#1 [used_trait_imports] finding used_trait_imports `foo_self_1::{constant#0}`
#2 [check_unused_traits] checking unused trait imports in crate
#3 [analysis] running analysis passes on crate `inherent_impls_enums`
end of query stack
error: aborting due to 5 previous errors

Some errors have detailed explanations: E0284, E0308.
For more information about an error, try `rustc --explain E0284`.
------------------------------------------

---- [ui] tests/ui/delegation/inherent-impls-enums.rs stdout end ----
---- [ui] tests/ui/delegation/inherent-impls-parent-generics.rs stdout ----

error: Error: expected failure status (Some(1)) but received status Some(101).
status: exit status: 101
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/delegation/inherent-impls-parent-generics.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2" "--target=aarch64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/delegation/inherent-impls-parent-generics" "-Znext-solver=coherence" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/aarch64-unknown-linux-gnu/native/rust-test-helpers"
stdout: none
--- stderr -------------------------------
error: inferred lifetimes are not allowed in delegations as we need to inherit signature
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:14:7
   |
LL | reuse E::foo_static as e;
   |       ^

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:14:7
   |
LL | reuse E::foo_static as e;
   |       ^ not allowed in type signatures

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:14:7
   |
LL | reuse E::foo_static as e;
   |       ^ not allowed in type signatures
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: inferred lifetimes are not allowed in delegations as we need to inherit signature
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:18:7
   |
LL | reuse E::foo_self as e1;
   |       ^

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:18:7
   |
LL | reuse E::foo_self as e1;
   |       ^ not allowed in type signatures

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:18:7
   |
LL | reuse E::foo_self as e1;
   |       ^ not allowed in type signatures
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: inferred lifetimes are not allowed in delegations as we need to inherit signature
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:24:7
   |
LL | reuse E::foo_static::<'static, (), true> as e2;
   |       ^

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:24:7
   |
LL | reuse E::foo_static::<'static, (), true> as e2;
   |       ^ not allowed in type signatures

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:24:7
   |
LL | reuse E::foo_static::<'static, (), true> as e2;
   |       ^ not allowed in type signatures
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: inferred lifetimes are not allowed in delegations as we need to inherit signature
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:28:7
   |
LL | reuse E::foo_self::<'static, (), true> as e3;
   |       ^

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:28:7
   |
LL | reuse E::foo_self::<'static, (), true> as e3;
   |       ^ not allowed in type signatures

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:28:7
   |
LL | reuse E::foo_self::<'static, (), true> as e3;
   |       ^ not allowed in type signatures
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: inferred lifetimes are not allowed in delegations as we need to inherit signature
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:40:11
   |
LL | reuse E::<'_, (), _>::foo_static as e8;
   |           ^^

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:40:19
   |
LL | reuse E::<'_, (), _>::foo_static as e8;
   |                   ^ not allowed in type signatures

error: inferred lifetimes are not allowed in delegations as we need to inherit signature
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:44:11
   |
LL | reuse E::<'_, _, _>::foo_self as e9;
   |           ^^

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:44:15
   |
LL | reuse E::<'_, _, _>::foo_self as e9;
   |               ^ not allowed in type signatures

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:44:18
   |
LL | reuse E::<'_, _, _>::foo_self as e9;
   |                  ^ not allowed in type signatures

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:59:7
   |
LL | reuse S::foo_static as s;
   |       ^ not allowed in type signatures

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:59:7
   |
LL | reuse S::foo_static as s;
   |       ^ not allowed in type signatures
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:63:7
   |
LL | reuse S::foo_self as s1;
   |       ^ not allowed in type signatures

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:63:7
   |
LL | reuse S::foo_self as s1;
   |       ^ not allowed in type signatures
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:68:7
   |
LL | reuse S::foo_static::<'static, (), true> as s2;
   |       ^ not allowed in type signatures

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:68:7
   |
LL | reuse S::foo_static::<'static, (), true> as s2;
   |       ^ not allowed in type signatures
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:72:7
   |
LL | reuse S::foo_self::<'static, (), true> as s3;
   |       ^ not allowed in type signatures

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:72:7
   |
LL | reuse S::foo_self::<'static, (), true> as s3;
   |       ^ not allowed in type signatures
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:83:15
   |
LL | reuse S::<(), _>::foo_static as s8;
   |               ^ not allowed in type signatures

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:86:11
   |
LL | reuse S::<_, 123>::foo_self as s9;
   |           ^ not allowed in type signatures

error[E0061]: this function takes 1 argument but 0 arguments were supplied
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:18:10
   |
LL | reuse E::foo_self as e1;
   |          ^^^^^^^^ argument #1 of type `E<'_, _, _>` is missing
   |
note: method defined here
  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:11:8
   |
LL |     fn foo_self<'d: 'd, 'e, T, const B: bool>(self) {}
   |        ^^^^^^^^                               ----
help: provide the argument
   |
LL | reuse E::foo_self(/* value */) as e1;
   |                  +++++++++++++

error[E0061]: this function takes 1 argument but 0 arguments were supplied
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:28:10
   |
LL | reuse E::foo_self::<'static, (), true> as e3;
   |          ^^^^^^^^ argument #1 of type `E<'_, _, _>` is missing
   |
note: method defined here
  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:11:8
   |
LL |     fn foo_self<'d: 'd, 'e, T, const B: bool>(self) {}
   |        ^^^^^^^^                               ----
help: provide the argument
   |
LL | reuse E::foo_self(/* value */)::<'static, (), true> as e3;
   |                  +++++++++++++

error[E0061]: this function takes 1 argument but 0 arguments were supplied
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:44:22
   |
LL | reuse E::<'_, _, _>::foo_self as e9;
   |                      ^^^^^^^^ argument #1 of type `E<'_, _, _>` is missing
   |
note: method defined here
  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:11:8
   |
LL |     fn foo_self<'d: 'd, 'e, T, const B: bool>(self) {}
   |        ^^^^^^^^                               ----
help: provide the argument
   |
LL | reuse E::<'_, _, _>::foo_self(/* value */) as e9;
   |                              +++++++++++++

error[E0061]: this function takes 1 argument but 0 arguments were supplied
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:63:10
   |
LL | reuse S::foo_self as s1;
   |          ^^^^^^^^ argument #1 of type `S<_, _>` is missing
   |
note: method defined here
  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:56:8
   |
LL |     fn foo_self<'d: 'd, 'e, T, const B: bool>(self) {}
   |        ^^^^^^^^                               ----
help: provide the argument
   |
LL | reuse S::foo_self(/* value */) as s1;
   |                  +++++++++++++

error[E0061]: this function takes 1 argument but 0 arguments were supplied
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:72:10
   |
LL | reuse S::foo_self::<'static, (), true> as s3;
   |          ^^^^^^^^ argument #1 of type `S<_, _>` is missing
   |
note: method defined here
  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:56:8
   |
LL |     fn foo_self<'d: 'd, 'e, T, const B: bool>(self) {}
   |        ^^^^^^^^                               ----
help: provide the argument
   |
LL | reuse S::foo_self(/* value */)::<'static, (), true> as s3;
   |                  +++++++++++++

error[E0061]: this function takes 1 argument but 0 arguments were supplied
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:86:20
   |
LL | reuse S::<_, 123>::foo_self as s9;
   |                    ^^^^^^^^ argument #1 of type `S<_, 123>` is missing
   |
note: method defined here
  --> /checkout/tests/ui/delegation/inherent-impls-parent-generics.rs:56:8
   |
LL |     fn foo_self<'d: 'd, 'e, T, const B: bool>(self) {}
   |        ^^^^^^^^                               ----
help: provide the argument
   |
LL | reuse S::<_, 123>::foo_self(/* value */) as s9;
   |                            +++++++++++++

##[error]error: internal compiler error: compiler/rustc_hir_typeck/src/lib.rs:127:9: can't type-check body of DefId(0:39 ~ inherent_impls_parent_generics[ca24]::e5::{constant#0})


thread 'rustc' (63770) panicked at compiler/rustc_hir_typeck/src/lib.rs:127:9:
Box<dyn Any>
stack backtrace:
   0: std::panicking::begin_panic::<rustc_errors::ExplicitBug>
   1: <rustc_errors::diagnostic::BugAbort as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
   2: <rustc_errors::DiagCtxtHandle>::span_bug::<rustc_span::span_encoding::Span, alloc::string::String>
   3: rustc_middle::util::bug::opt_span_bug_fmt::<rustc_span::span_encoding::Span>::{closure#0}
   4: rustc_middle::ty::context::tls::with_opt::<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}
   5: rustc_middle::ty::context::tls::with_context_opt::<rustc_middle::ty::context::tls::with_opt<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
   6: rustc_middle::util::bug::span_bug_fmt::<rustc_span::span_encoding::Span>
   7: rustc_hir_typeck::typeck_with_inspect::{closure#0}::{closure#0}
---
  11: rustc_hir_analysis::check_unused::check_unused_traits
      [... omitted 2 frames ...]
  12: rustc_hir_analysis::check_crate
  13: rustc_interface::passes::analysis
      [... omitted 2 frames ...]
  14: std::panicking::catch_unwind::<core::option::Option<rustc_interface::queries::Linker>, core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#1}>::{closure#2}::{closure#0}>>
  15: <std::thread::local::LocalKey<core::cell::Cell<*const ()>>>::with::<rustc_middle::ty::context::tls::enter_context<<rustc_middle::ty::context::GlobalCtxt>::enter<rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#1}>::{closure#2}, core::option::Option<rustc_interface::queries::Linker>>::{closure#1}, core::option::Option<rustc_interface::queries::Linker>>::{closure#0}, core::option::Option<rustc_interface::queries::Linker>>
  16: <rustc_middle::ty::context::TyCtxt>::create_global_ctxt::<core::option::Option<rustc_interface::queries::Linker>, rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#1}>::{closure#2}>
  17: rustc_interface::passes::create_and_enter_global_ctxt::<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#1}>
  18: std::panicking::catch_unwind::<(), core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#2}::{closure#0}>>
  19: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#2}
  20: rustc_span::create_session_globals_then::<(), rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#2}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}::{closure#0}>
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: please make sure that you have updated to the latest nightly

note: rustc 1.100.0-nightly (a5ce51d0a 2026-09-02) running on aarch64-unknown-linux-gnu

note: compiler flags: -Z simulate-remapped-rust-src-base=/rustc/FAKE_PREFIX -Z translate-remapped-path-to-local-path=no -Z ignore-directory-in-diagnostics-source-blocks=/cargo -Z ignore-directory-in-diagnostics-source-blocks=/checkout/vendor -C codegen-units=1 -Z ui-testing -Z deduplicate-diagnostics=no -Z write-long-types-to-disk=no -C strip=debuginfo -C prefer-dynamic -Z next-solver=coherence -C rpath -C debuginfo=0

query stack during panic:
#0 [typeck_root] type-checking `e5::{constant#0}`
#1 [used_trait_imports] finding used_trait_imports `e5::{constant#0}`
#2 [check_unused_traits] checking unused trait imports in crate
#3 [analysis] running analysis passes on crate `inherent_impls_parent_generics`
end of query stack
error: aborting due to 34 previous errors

Some errors have detailed explanations: E0061, E0121.
For more information about an error, try `rustc --explain E0061`.
------------------------------------------

---- [ui] tests/ui/delegation/inherent-impls-parent-generics.rs stdout end ----
---- [ui] tests/ui/delegation/inherent-impls-self-replacement.rs stdout ----

error: Error: expected failure status (Some(1)) but received status Some(101).
status: exit status: 101
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/delegation/inherent-impls-self-replacement.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2" "--target=aarch64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/delegation/inherent-impls-self-replacement" "-Znext-solver=coherence" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/aarch64-unknown-linux-gnu/native/rust-test-helpers"
stdout: none
--- stderr -------------------------------
error[E0308]: mismatched types
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-self-replacement.rs:30:34
   |
LL |     reuse S::<(), 123>::by_box { self.get_s() }
   |                         ------   ^^^^^^^^^^^^ expected `Box<S<(), 123>>`, found `S<(), 123>`
   |                         |
   |                         arguments to this function are incorrect
   |
   = note: expected struct `Box<S<_, _>>`
              found struct `S<_, _>`
   = note: for more on the distinction between the stack and the heap, read https://doc.rust-lang.org/book/ch15-01-box.html, https://doc.rust-lang.org/rust-by-example/std/box.html, and https://doc.rust-lang.org/std/boxed/index.html
note: method defined here
  --> /checkout/tests/ui/delegation/inherent-impls-self-replacement.rs:14:8
   |
LL |     fn by_box<'d: 'd, 'e, T, const B: bool>(self: Box<Self>) {}
   |        ^^^^^^                               ----
help: store this in the heap by calling `Box::new`
   |
LL |     reuse S::<(), 123>::by_box { Box::new(self.get_s()) }
   |                                  +++++++++            +

error[E0308]: mismatched types
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-self-replacement.rs:33:33
   |
LL |     reuse S::<(), 123>::by_rc { self.get_s() }
   |                         -----   ^^^^^^^^^^^^ expected `Rc<S<(), 123>>`, found `S<(), 123>`
   |                         |
   |                         arguments to this function are incorrect
   |
   = note: expected struct `Rc<S<_, _>>`
              found struct `S<_, _>`
note: method defined here
  --> /checkout/tests/ui/delegation/inherent-impls-self-replacement.rs:15:8
   |
LL |     fn by_rc<'d: 'd, 'e, T, const B: bool>(self: Rc<Self>) {}
   |        ^^^^^                               ----
help: call `Into::into` on this expression to convert `S<(), 123>` into `Rc<S<(), 123>>`
   |
LL |     reuse S::<(), 123>::by_rc { self.get_s().into() }
   |                                             +++++++

error[E0308]: mismatched types
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-self-replacement.rs:36:34
   |
LL |     reuse S::<(), 123>::by_pin { self.get_s() }
   |                         ------   ^^^^^^^^^^^^ expected `Pin<Box<S<(), 123>>>`, found `S<(), 123>`
   |                         |
   |                         arguments to this function are incorrect
   |
   = note: expected struct `Pin<Box<S<(), 123>>>`
              found struct `S<(), 123>`
note: method defined here
  --> /checkout/tests/ui/delegation/inherent-impls-self-replacement.rs:16:8
   |
LL |     fn by_pin<'d: 'd, 'e, T, const B: bool>(self: Pin<Box<Self>>) {}
   |        ^^^^^^                               ----
help: you need to pin and box this expression
   |
LL |     reuse S::<(), 123>::by_pin { Box::pin(self.get_s()) }
   |                                  +++++++++            +

error[E0599]: no method named `get_s` found for type parameter `Self` in the current scope
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-self-replacement.rs:41:41
   |
LL | trait Trait2: Sized {
   | ------------------- method `get_s` not found for this type parameter
LL |     reuse S::<(), 123>::by_value { self.get_s() }
   |                                         ^^^^^ method not found in `Self`
   |
   = help: items from traits can only be used if the type parameter is bounded by the trait
help: the following trait defines an item `get_s`, perhaps you need to add another supertrait for it:
   |
LL | trait Trait2: Sized + Trait {
   |                     +++++++

error[E0599]: no method named `get_s` found for reference `&Self` in the current scope
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-self-replacement.rs:43:39
   |
LL |     reuse S::<(), 123>::by_ref { self.get_s() }
   |                                       ^^^^^ method not found in `&Self`
   |
   = help: items from traits can only be used if the type parameter is bounded by the trait
help: the following trait defines an item `get_s`, perhaps you need to add another supertrait for it:
   |
LL | trait Trait2: Sized + Trait {
   |                     +++++++

error[E0599]: no method named `get_s` found for mutable reference `&mut Self` in the current scope
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-self-replacement.rs:45:43
   |
LL |     reuse S::<(), 123>::by_mut_ref { self.get_s() }
   |                                           ^^^^^ method not found in `&mut Self`
   |
   = help: items from traits can only be used if the type parameter is bounded by the trait
help: the following trait defines an item `get_s`, perhaps you need to add another supertrait for it:
   |
LL | trait Trait2: Sized + Trait {
   |                     +++++++

error[E0599]: no method named `get_s` found for struct `Box<Self>` in the current scope
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-self-replacement.rs:47:39
   |
LL |     reuse S::<(), 123>::by_box { self.get_s() }
   |                                       ^^^^^ method not found in `Box<Self>`
   |
   = help: items from traits can only be used if the trait is implemented and in scope
note: `Trait` defines an item `get_s`, perhaps you need to implement it
  --> /checkout/tests/ui/delegation/inherent-impls-self-replacement.rs:19:1
   |
LL | trait Trait: Sized {
   | ^^^^^^^^^^^^^^^^^^

error[E0599]: no method named `get_s` found for struct `Rc<Self>` in the current scope
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-self-replacement.rs:49:38
   |
LL |     reuse S::<(), 123>::by_rc { self.get_s() }
   |                                      ^^^^^ method not found in `Rc<Self>`
   |
   = help: items from traits can only be used if the trait is implemented and in scope
note: `Trait` defines an item `get_s`, perhaps you need to implement it
  --> /checkout/tests/ui/delegation/inherent-impls-self-replacement.rs:19:1
   |
LL | trait Trait: Sized {
   | ^^^^^^^^^^^^^^^^^^

error[E0599]: no method named `get_s` found for struct `Pin<Box<Self>>` in the current scope
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-self-replacement.rs:51:39
   |
LL |     reuse S::<(), 123>::by_pin { self.get_s() }
   |                                       ^^^^^ method not found in `Pin<Box<Self>>`
   |
   = help: items from traits can only be used if the trait is implemented and in scope
note: `Trait` defines an item `get_s`, perhaps you need to implement it
  --> /checkout/tests/ui/delegation/inherent-impls-self-replacement.rs:19:1
   |
LL | trait Trait: Sized {
   | ^^^^^^^^^^^^^^^^^^

##[error]error: internal compiler error: compiler/rustc_hir_typeck/src/lib.rs:127:9: can't type-check body of DefId(0:50 ~ inherent_impls_self_replacement[2404]::Trait::by_value::{constant#0})
  --> /checkout/tests/ui/delegation/inherent-impls-self-replacement.rs:22:25
   |
LL |     reuse S::<(), 123>::by_value { self.get_s() }
   |                         ^^^^^^^^


thread 'rustc' (63802) panicked at compiler/rustc_hir_typeck/src/lib.rs:127:9:
Box<dyn Any>
stack backtrace:
   0: std::panicking::begin_panic::<rustc_errors::ExplicitBug>
   1: <rustc_errors::diagnostic::BugAbort as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
   2: <rustc_errors::DiagCtxtHandle>::span_bug::<rustc_span::span_encoding::Span, alloc::string::String>
   3: rustc_middle::util::bug::opt_span_bug_fmt::<rustc_span::span_encoding::Span>::{closure#0}
   4: rustc_middle::ty::context::tls::with_opt::<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}
   5: rustc_middle::ty::context::tls::with_context_opt::<rustc_middle::ty::context::tls::with_opt<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
   6: rustc_middle::util::bug::span_bug_fmt::<rustc_span::span_encoding::Span>
   7: rustc_hir_typeck::typeck_with_inspect::{closure#0}::{closure#0}
---
  11: rustc_hir_analysis::check_unused::check_unused_traits
      [... omitted 2 frames ...]
  12: rustc_hir_analysis::check_crate
  13: rustc_interface::passes::analysis
      [... omitted 2 frames ...]
  14: std::panicking::catch_unwind::<core::option::Option<rustc_interface::queries::Linker>, core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#1}>::{closure#2}::{closure#0}>>
  15: <std::thread::local::LocalKey<core::cell::Cell<*const ()>>>::with::<rustc_middle::ty::context::tls::enter_context<<rustc_middle::ty::context::GlobalCtxt>::enter<rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#1}>::{closure#2}, core::option::Option<rustc_interface::queries::Linker>>::{closure#1}, core::option::Option<rustc_interface::queries::Linker>>::{closure#0}, core::option::Option<rustc_interface::queries::Linker>>
  16: <rustc_middle::ty::context::TyCtxt>::create_global_ctxt::<core::option::Option<rustc_interface::queries::Linker>, rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#1}>::{closure#2}>
  17: rustc_interface::passes::create_and_enter_global_ctxt::<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#1}>
  18: std::panicking::catch_unwind::<(), core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#2}::{closure#0}>>
  19: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#2}
  20: rustc_span::create_session_globals_then::<(), rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#2}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}::{closure#0}>
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: please make sure that you have updated to the latest nightly

note: rustc 1.100.0-nightly (a5ce51d0a 2026-09-02) running on aarch64-unknown-linux-gnu

note: compiler flags: -Z simulate-remapped-rust-src-base=/rustc/FAKE_PREFIX -Z translate-remapped-path-to-local-path=no -Z ignore-directory-in-diagnostics-source-blocks=/cargo -Z ignore-directory-in-diagnostics-source-blocks=/checkout/vendor -C codegen-units=1 -Z ui-testing -Z deduplicate-diagnostics=no -Z write-long-types-to-disk=no -C strip=debuginfo -C prefer-dynamic -Z next-solver=coherence -C rpath -C debuginfo=0

query stack during panic:
#0 [typeck_root] type-checking `Trait::by_value::{constant#0}`
#1 [used_trait_imports] finding used_trait_imports `Trait::by_value::{constant#0}`
#2 [check_unused_traits] checking unused trait imports in crate
#3 [analysis] running analysis passes on crate `inherent_impls_self_replacement`
end of query stack
error: aborting due to 10 previous errors

Some errors have detailed explanations: E0308, E0599.
For more information about an error, try `rustc --explain E0308`.
------------------------------------------

---- [ui] tests/ui/delegation/inherent-impls-self-replacement.rs stdout end ----
---- [ui] tests/ui/delegation/inherent-impls-structs.rs stdout ----

error: Error: expected failure status (Some(1)) but received status Some(101).
status: exit status: 101
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/delegation/inherent-impls-structs.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2" "--target=aarch64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/delegation/inherent-impls-structs" "-Znext-solver=coherence" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/aarch64-unknown-linux-gnu/native/rust-test-helpers"
stdout: none
--- stderr -------------------------------
error[E0308]: mismatched types
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-structs.rs:31:23
   |
LL | trait Trait<'a, AA, BB> where Self: Sized {
   | ----------------------- found this type parameter
...
LL |     reuse S::<(), 1>::foo_self::<'static, _, _> as foo_self_4;
   |                       ^^^^^^^^
   |                       |
   |                       expected `S<(), 1>`, found type parameter `Self`
   |                       arguments to this function are incorrect
   |
   = note:      expected struct `S<(), 1>`
           found type parameter `Self`
note: method defined here
  --> /checkout/tests/ui/delegation/inherent-impls-structs.rs:9:8
   |
LL |     fn foo_self<'d: 'd, 'e, T, const B: bool>(self) {}
   |        ^^^^^^^^                               ----

error[E0284]: type annotations needed
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-structs.rs:40:23
   |
LL |     reuse S::<(), 1>::foo_static::<'static, _, _> as foo_static_4;
   |                       ^^^^^^^^^^ cannot infer the value of const parameter `B` declared on the associated function `foo_static`
   |
note: required by a const generic parameter in `S::<A, C>::foo_static`
  --> /checkout/tests/ui/delegation/inherent-impls-structs.rs:8:34
   |
LL |     fn foo_static<'d: 'd, 'e, T, const B: bool>() {}
   |                                  ^^^^^^^^^^^^^ required by this const generic parameter in `S::<A, C>::foo_static`

error[E0308]: mismatched types
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-structs.rs:45:23
   |
LL |     reuse S::<(), 1>::foo_self::<'static, _, _> as foo_self_4;
   |                       ^^^^^^^^
   |                       |
   |                       expected `S<(), 1>`, found `X`
   |                       arguments to this function are incorrect
   |
   = note: expected struct `S<(), 1>`
              found struct `X`
note: method defined here
  --> /checkout/tests/ui/delegation/inherent-impls-structs.rs:9:8
   |
LL |     fn foo_self<'d: 'd, 'e, T, const B: bool>(self) {}
   |        ^^^^^^^^                               ----

error[E0308]: mismatched types
##[error]  --> /checkout/tests/ui/delegation/inherent-impls-structs.rs:60:23
   |
LL |     reuse S::<(), 1>::foo_self::<'static, _, _> as foo_self_4;
   |                       ^^^^^^^^
   |                       |
   |                       expected `S<(), 1>`, found `X`
   |                       arguments to this function are incorrect
   |
   = note: expected struct `S<(), 1>`
              found struct `X`
note: method defined here
  --> /checkout/tests/ui/delegation/inherent-impls-structs.rs:9:8
   |
LL |     fn foo_self<'d: 'd, 'e, T, const B: bool>(self) {}
   |        ^^^^^^^^                               ----

##[error]error: internal compiler error: compiler/rustc_hir_typeck/src/lib.rs:127:9: can't type-check body of DefId(0:32 ~ inherent_impls_structs[4d20]::foo_self_1::{constant#0})
  --> /checkout/tests/ui/delegation/inherent-impls-structs.rs:16:19
   |
LL | reuse S::<(), 1>::foo_self::<'static, (), true> as foo_self_1;
   |                   ^^^^^^^^


thread 'rustc' (63804) panicked at compiler/rustc_hir_typeck/src/lib.rs:127:9:
Box<dyn Any>
stack backtrace:
   0: std::panicking::begin_panic::<rustc_errors::ExplicitBug>
   1: <rustc_errors::diagnostic::BugAbort as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
   2: <rustc_errors::DiagCtxtHandle>::span_bug::<rustc_span::span_encoding::Span, alloc::string::String>
   3: rustc_middle::util::bug::opt_span_bug_fmt::<rustc_span::span_encoding::Span>::{closure#0}
   4: rustc_middle::ty::context::tls::with_opt::<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}
   5: rustc_middle::ty::context::tls::with_context_opt::<rustc_middle::ty::context::tls::with_opt<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
   6: rustc_middle::util::bug::span_bug_fmt::<rustc_span::span_encoding::Span>
   7: rustc_hir_typeck::typeck_with_inspect::{closure#0}::{closure#0}
---
  11: rustc_hir_analysis::check_unused::check_unused_traits
      [... omitted 2 frames ...]
  12: rustc_hir_analysis::check_crate
  13: rustc_interface::passes::analysis
      [... omitted 2 frames ...]
  14: std::panicking::catch_unwind::<core::option::Option<rustc_interface::queries::Linker>, core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#1}>::{closure#2}::{closure#0}>>
  15: <std::thread::local::LocalKey<core::cell::Cell<*const ()>>>::with::<rustc_middle::ty::context::tls::enter_context<<rustc_middle::ty::context::GlobalCtxt>::enter<rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#1}>::{closure#2}, core::option::Option<rustc_interface::queries::Linker>>::{closure#1}, core::option::Option<rustc_interface::queries::Linker>>::{closure#0}, core::option::Option<rustc_interface::queries::Linker>>
  16: <rustc_middle::ty::context::TyCtxt>::create_global_ctxt::<core::option::Option<rustc_interface::queries::Linker>, rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#1}>::{closure#2}>
  17: rustc_interface::passes::create_and_enter_global_ctxt::<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#1}>
  18: std::panicking::catch_unwind::<(), core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#2}::{closure#0}>>
  19: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#2}
  20: rustc_span::create_session_globals_then::<(), rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#2}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}::{closure#0}>
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: please make sure that you have updated to the latest nightly

note: rustc 1.100.0-nightly (a5ce51d0a 2026-09-02) running on aarch64-unknown-linux-gnu

note: compiler flags: -Z simulate-remapped-rust-src-base=/rustc/FAKE_PREFIX -Z translate-remapped-path-to-local-path=no -Z ignore-directory-in-diagnostics-source-blocks=/cargo -Z ignore-directory-in-diagnostics-source-blocks=/checkout/vendor -C codegen-units=1 -Z ui-testing -Z deduplicate-diagnostics=no -Z write-long-types-to-disk=no -C strip=debuginfo -C prefer-dynamic -Z next-solver=coherence -C rpath -C debuginfo=0

query stack during panic:
#0 [typeck_root] type-checking `foo_self_1::{constant#0}`
#1 [used_trait_imports] finding used_trait_imports `foo_self_1::{constant#0}`
#2 [check_unused_traits] checking unused trait imports in crate
#3 [analysis] running analysis passes on crate `inherent_impls_structs`
end of query stack
error: aborting due to 5 previous errors

Some errors have detailed explanations: E0284, E0308.
For more information about an error, try `rustc --explain E0284`.

rust-bors · 2026-09-03T16:45:29Z

☔ The latest upstream changes (presumably #162229) made this pull request unmergeable. Please resolve the merge conflicts by rebasing.

rustbot assigned petrochenkov Sep 2, 2026

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rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Sep 2, 2026

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rust-bors Bot pushed a commit that referenced this pull request Sep 2, 2026

Auto merge of #162190 - aerooneqq:delegation-inh-impls-fair-resolutio…

8ac1108

…n, r=<try> delegation: supporting fair resolution for delegations to inherent impls

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aerooneqq added 17 commits September 2, 2026 16:53

Initial support for delegations to inherent functions

53958b1

Fix tests

274997f

Better handling of wrong args in inherent impl

f872755

Fix incorrect signature update

ab0e2e1

Cleanups + add test for self type mapping in inherent impls

d2f4ce2

Force specification of parent generics in inherent impls

64cac60

Cleanup tests

5791b53

Ban infers in parent segments of delegations to inherent impls

bdc9c7a

Fix arguments mapping, remove not needed check

64aab4f

Fix not adjusting all signature when delegating to inherent impl

a2a1393

Cleanups

d07ebcd

Cleanups

32a7a40

Comment + add test for rename

c483069

Fix tests

e8f3a35

Cleanups and comments

508cfc9

wip

70929e4

wip

904cb0c

aerooneqq added 5 commits September 2, 2026 16:53

wip

35f455e

wip

84008f5

wip

6fb4466

Cleanups

8202a8f

Fix checks

193c5b5

aerooneqq force-pushed the delegation-inh-impls-fair-resolution branch from be08fbc to 193c5b5 Compare September 2, 2026 13:57

rustbot added perf-regression Performance regression. and removed S-waiting-on-perf Status: Waiting on a perf run to be completed. labels Sep 2, 2026

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delegation: supporting fair resolution for delegations to inherent impls - #162190

delegation: supporting fair resolution for delegations to inherent impls#162190
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rust-timer commented Sep 2, 2026

Overall result: ❌✅ regressions and improvements - please read:

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