Retpoline-related cfgs seems to be gone on nightly

[HadrienG2]

Per my nightly periodical CI log: https://github.com/HadrienG2/iterator_ilp/actions/runs/11963978141/job/33355466714 . Not sure if you can access it, if not here's the relevant part:

error: unexpected `cfg` condition value: `retpoline`
Error:  --> benches/benchmark.rs:9:1
  |
9 | #[multiversion(targets = "simd")]
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: expected values for `target_feature` are: `10e60`, `2e3`, `3e3r1`, `3e3r2`, `3e3r3`, `3e7`, `7e10`, `a`, `aclass`, `adx`, `aes`, `altivec`, `alu32`, `amx-bf16`, `amx-complex`, `amx-fp16`, `amx-int8`, `amx-tile`, `atomics`, `avx`, `avx2`, `avx512bf16`, `avx512bitalg`, `avx512bw`, `avx512cd`, `avx512dq`, `avx512f`, `avx512fp16`, `avx512ifma`, `avx512vbmi`, `avx512vbmi2`, `avx512vl`, `avx512vnni`, `avx512vp2intersect`, and `avx512vpopcntdq` and 251 more
  = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
  = note: `-D unexpected-cfgs` implied by `-D warnings`
  = help: to override `-D warnings` add `#[allow(unexpected_cfgs)]`
  = note: this error originates in the attribute macro `multiversion` (in Nightly builds, run with -Z macro-backtrace for more info)

error: unexpected `cfg` condition value: `retpoline-indirect-branches`
Error:  --> benches/benchmark.rs:9:1
  |
9 | #[multiversion(targets = "simd")]
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: expected values for `target_feature` are: `10e60`, `2e3`, `3e3r1`, `3e3r2`, `3e3r3`, `3e7`, `7e10`, `a`, `aclass`, `adx`, `aes`, `altivec`, `alu32`, `amx-bf16`, `amx-complex`, `amx-fp16`, `amx-int8`, `amx-tile`, `atomics`, `avx`, `avx2`, `avx512bf16`, `avx512bitalg`, `avx512bw`, `avx512cd`, `avx512dq`, `avx512f`, `avx512fp16`, `avx512ifma`, `avx512vbmi`, `avx512vbmi2`, `avx512vl`, `avx512vnni`, `avx512vp2intersect`, and `avx512vpopcntdq` and 251 more
  = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
  = note: this error originates in the attribute macro `multiversion` (in Nightly builds, run with -Z macro-backtrace for more info)

error: unexpected `cfg` condition value: `retpoline-indirect-calls`
Error:  --> benches/benchmark.rs:9:1
  |
9 | #[multiversion(targets = "simd")]
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: expected values for `target_feature` are: `10e60`, `2e3`, `3e3r1`, `3e3r2`, `3e3r3`, `3e7`, `7e10`, `a`, `aclass`, `adx`, `aes`, `altivec`, `alu32`, `amx-bf16`, `amx-complex`, `amx-fp16`, `amx-int8`, `amx-tile`, `atomics`, `avx`, `avx2`, `avx512bf16`, `avx512bitalg`, `avx512bw`, `avx512cd`, `avx512dq`, `avx512f`, `avx512fp16`, `avx512ifma`, `avx512vbmi`, `avx512vbmi2`, `avx512vl`, `avx512vnni`, `avx512vp2intersect`, and `avx512vpopcntdq` and 251 more
  = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
  = note: this error originates in the attribute macro `multiversion` (in Nightly builds, run with -Z macro-backtrace for more info)

error: could not compile `iterator_ilp` (bench "benchmark") due to 3 previous errors
warning: build failed, waiting for other jobs to finish...
Error: Process completed with exit code 101.

It seems multiversion will need some adaptations to work on newer nightlies and future beta/stable.

[calebzulawski]

I wonder if this is a regression in cfg checking, as far as I can tell those target features still exist.

[calebzulawski]

I think this is caused by rust-lang/rust#132577