chore(deps): bump libc from 0.2.186 to 0.2.188

[dependabot]

Bumps libc from 0.2.186 to 0.2.188.

Release notes

Sourced from libc's releases.

0.2.188

Changed

• Restore Send and Sync for DIR (35b062263401)

These were removed in 0.2.187 because libc does not actually make Send and Sync guarantees about DIR (or other extern types), but this caused some crates to break. The traits are added back for now to allow time to migrate, but will be removed again in the future; please make sure your crates are not relying on libc::DIR: Send or libc::DIR: Sync.

0.2.187

This release contains a number of improvements related to 64-bit time_t configuration. Of note the existing RUST_LIBC_UNSTABLE_* environment variables have been replaced with configuration options. The new way to use these is:

RUSTFLAGS='--cfg=libc_unstable_musl_v1_2_3' cargo ...
RUSTFLAGS='--cfg=libc_unstable_gnu_time_bits="64"' cargo ...

Being able to set this via RUSTFLAGS makes it easier to only apply configuration to specific targets (and notably, not the host if build scripts are used).

There are two other notable changes:

• The 32-bit windows-gnu targets now respect libc_unstable_gnu_time_bits

• uClibc now supports a similar configuration option:

  RUSTFLAGS='--cfg=libc_unstable_uclibc_time64'

As a reminder, these options are under active development and may change in the future (hence the "unstable" in the name). It likely that we will harmonize everything under a single configuration option before considering them stable.

Support

• Add support for aarch64-unknown-linux-pauthtest (#5065)
• Add support for new QNX targets (#5241)
• Better document breaking change policy and recommended usage (#5179)

Added

• Android: Add POSIX_SPAWN_* constants (#5104)
• Android: Add getpwent, setpwent, and endpwent (#5160)
• Android: Add preadv2 and pwritev2 (#5157)
• Android: Add seccomp_notif* structures (#5224)
• Android: Add timer_[create, delete, getoverrun, gettime, settime] (#5108)

... (truncated)

Changelog

Sourced from libc's changelog.

0.2.188 - 2026-07-21

Changed

• Restore Send and Sync for DIR (35b062263401)

These were removed in 0.2.187 because libc does not actually make Send and Sync guarantees about DIR (or other extern types), but this caused some crates to break. The traits are added back for now to allow time to migrate, but will be removed again in the future; please make sure your crates are not relying on libc::DIR: Send or libc::DIR: Sync.

0.2.187 - 2026-07-20

This release contains a number of improvements related to 64-bit time_t configuration. Of note the existing RUST_LIBC_UNSTABLE_* environment variables have been replaced with configuration options. The new way to use these is:

RUSTFLAGS='--cfg=libc_unstable_musl_v1_2_3' cargo ...
RUSTFLAGS='--cfg=libc_unstable_gnu_time_bits="64"' cargo ...

Being able to set this via RUSTFLAGS makes it easier to only apply configuration to specific targets (and notably, not the host if build scripts are used).

There are two other notable changes:

• The 32-bit windows-gnu targets now respect libc_unstable_gnu_time_bits

• uClibc now supports a similar configuration option:

  RUSTFLAGS='--cfg=libc_unstable_uclibc_time64'

As a reminder, these options are under active development and may change in the future (hence the "unstable" in the name). It likely that we will harmonize everything under a single configuration option before considering them stable.

Support

• Add support for aarch64-unknown-linux-pauthtest (#5065)
• Add support for new QNX targets (#5241)
• Better document breaking change policy and recommended usage (#5179)

Added

• Android: Add POSIX_SPAWN_* constants (#5104)
• Android: Add getpwent, setpwent, and endpwent (#5160)

... (truncated)

Commits

• 7b7b771 libc: Release 0.2.188
• ba6a6b5 [0.2] Restore Send and Sync for DIR
• ee05190 libc: Release 0.2.187
• 13b2218 unix: add preadv2 and pwritev2 to android
• abc9903 docs: Improve the pull request template and CONTRIBUTING.md
• c452b48 util: Restructure to use one class per subcommand
• cbc70c9 nuttx: more document comments
• 2589ea3 nuttx: add TCP_MAXSEG definitions
• 6be50c1 nuttx: add pipe2 definitions
• 4500344 nuttx: add poll definitions
• Additional commits viewable in compare view

[dependabot]

Superseded by #633.