Standard library fails to build for arm64_32-apple-watchos

[Thomasdezeeuw]

Building the latest nightly with --target arm64_32-apple-watchos, fails with the following:

  error[E0308]: mismatched types
     --> /home/runner/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/sys/pal/unix/sync/condvar.rs:123:21
      |
  123 |             tv_sec: dur.as_secs() as i64,
      |                     ^^^^^^^^^^^^^^^^^^^^ expected `i32`, found `i64`
  
  error[E0308]: mismatched types
     --> /home/runner/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/sys/pal/unix/sync/condvar.rs:124:22
      |
  124 |             tv_nsec: dur.subsec_nanos() as i64,
      |                      ^^^^^^^^^^^^^^^^^^^^^^^^^ expected `i32`, found `i64`

Meta

rustc --version --verbose:

rustc 1.92.0-nightly (57ef8d642 2025-10-15)
binary: rustc
commit-hash: 57ef8d642d21965304bde849bab4f389b4353e27
commit-date: 2025-10-15
host: x86_64-unknown-linux-gnu
release: 1.92.0-nightly
LLVM version: 21.1.3

Backtrace

<backtrace>

[Noratrieb]

@deg4uss3r @vladimir-ea @leohowell @madsmtm

[madsmtm]

Introduced in #146503, I suspect it fails on other 32-bit targets as well.

CC @joboet, do you wanna take a look, or should I?

[Thomasdezeeuw]

Introduced in #146503, I suspect it fails on other 32-bit targets as well.

Note that the this is arm64_32 a somewhat weird 64 bit, but using 32 bits target. I think changing the as i64 to as _ would solve it, but not sure.

[madsmtm]

There's a comment right above that talks about why as i64 won't overflow, something about the duration being clamped, that should probably be reconsidered on 32-bit hardware, which is why I didn't just submit a quick fix.