Bump libc to 0.2.171 to use sigaction for AIX

[xingxue-ibm]

Change to use sa_sigaction instead of sa_union.__su_sigaction, now that the libc crate 0.2.171 implementation for AIX defines sa_sigaction as a direct member of struct sigaction, aligning it with implementations on other similar platforms. (rust-lang/libc#4250).

[vorner]

Hello

The changes look nice. However, you update the libc only in Cargo.lock ‒ which is only internal (for development) and downstream crates don't take it into account at all. Can you also mandate the right minimal libc in Cargo.toml?

[xingxue-ibm]

Hello

The changes look nice. However, you update the libc only in Cargo.lock ‒ which is only internal (for development) and downstream crates don't take it into account at all. Can you also mandate the right minimal libc in Cargo.toml?

Thanks for pointing this out! Changed Cargo.toml to mandate minimal libc version 0.2.171.

[xingxue-ibm]

Gentle ping. We cannot build russh on AIX without the fix:

error[E0609]: no field `sa_union` on type `sigaction`
   --> /home/rust/dev/cargo/registry/src/index.crates.io-d11c229612889eed/signal-hook-registry-1.4.2/src/lib.rs:164:15
    |
164 |         { new.sa_union.__su_sigaction = handler; }
    |               ^^^^^^^^ unknown field
    |
    = note: available fields are: `sa_sigaction`, `sa_mask`, `sa_flags`

[daltenty]

LGTM from the AIX perspective

[xingxue-ibm]

Gentle ping...

[vorner]

Sorry for late response, too little time… Released as 1.4.3.

[xingxue-ibm]

Sorry for late response, too little time… Released as 1.4.3.

No worries, thanks so much!