4.2.4

Bear 4.2.4 is a maintenance release. It fixes a hang when appending to a
truncated database, records MSVC environment flags correctly, builds for
Android without patches, and makes packaging easier. Building Bear now needs
Rust 1.89.

Features

• LIBEXECDIR install variable - scripts/install.sh can now put Bear's
  helpers somewhere other than $PREFIX/libexec, for distributions without
  that directory. For example, PREFIX=/usr LIBEXECDIR=/usr/lib. Like
  PREFIX, it is an on-system path and DESTDIR is prepended to it.

Bug Fixes

• Append no longer hangs on a broken database - appending to an empty or
  truncated compile_commands.json hung forever and flooded stderr with
  "failed to fill whole buffer". Bear now warns and goes on.
• MSVC CL and _CL_ values keep their backslashes - they were split
  with POSIX shell rules, so CL="/IC:\foo /W4" became /IC:foo. They now
  use Windows command-line rules.
• The compiler stays first in an entry - with CL=/O2 or
  ARMCOMPILER6_CLANGOPT, the added flags landed before the compiler, so
  arguments[0] was not the compiler.
• Ada body files are recognized - a typo in the extension list matched
  .abd instead of .adb.
• Drops from an unresolved directory are counted - with the canonical
  directory format, an entry whose working directory could not be resolved
  was dropped with a vague warning and left out of the summary. Bear now
  warns once per file and counts these drops, so a run that drops every
  entry this way gives the all-dropped error.
• Wrapper mode rewrites only compiler program variables - CARGO,
  RUSTC and RUSTC_WRAPPER are no longer pointed at wrappers, so cargo
  builds run untouched. CMake's language variables are added, so a CUDACXX
  or OBJC compiler is wrapped too. The make *FLAGS variables are no longer
  kept in the captured environment. If you read that environment from the
  events file, note the change.
• An empty compiler variable now logs a warning - as a whitespace-only
  value already did.
• Android builds without patches - the supervisor no longer needs
  confstr. The preload library leaves popen, pclose and system to
  bionic, and keeps the exec family. posix_spawn and posix_spawnp are
  intercepted on API 28 and later only.
• Build probes check the target - cross builds used the answers from the
  host libc. Symbol probes now link against the target libc, and a missing
  execve shows the compiler's output.
• The preload library build picks a linker that works - each linker is
  tried with a small test link first. The rust-lld from rustup, which has no
  zlib support, is skipped on hosts such as FreeBSD, and Bear reports the
  downgrade. (#722)
• The preload library installs as an executable - mode 0755, so RPM's
  debuginfo and strip steps process it. openSUSE, Slackware and Fedora no
  longer need their own chmod or install step.
• Removed the musl __execvpe wrapper. musl does not export that symbol, so
  it could never run.

Internal Refactoring

• Rust 1.89 is now required and declared - INSTALL.md said 1.85, but
  the code already needed more. An older toolchain now fails with a clear
  message instead of a compile error.
• Fewer dependencies - tempfile left the shipped binaries, and five
  crates with it. crossbeam-channel was replaced by std channels.
• Moved to serde-saphyr 2.0. Updated cc, insta and proptest.
• Stricter lints: no unwrap outside test code, a SAFETY comment on every
  unsafe block, and a reason on every allow.
• CI now runs the tests on Alpine (musl) and aarch64 Linux, cross-builds for
  Android, and checks crates with cargo-deny, with advisories on a schedule.
• Build warnings fixed for hosts without setsid, and a test fixed for
  hosts where execvp cannot be intercepted. (#720, #721)

Documentation

• The requirements and rationale were swept and trimmed, with one owner for
  each fact.

Thanks

Thanks to @aokblast for the FreeBSD fixes in #720, #721 and #722. The linker
problem they found hit any host whose system objects use zlib-compressed debug
sections. Thanks to @Jugst3r for the Ada fix in #719.

Thanks to the downstream packagers who keep Bear available and current -
chronically invisible work that this project depends on. Everyone below
shipped 4.2.3:

• Alpine - @rtmongold
• Arch, Artix, Manjaro, and Parabola maintainers
• Homebrew
• MSYS2
• Nix maintainers
• openSUSE Tumbleweed
• Termux - @nguynkhn

New Contributors

• @Jugst3r made their first contribution in #719

Full Changelog: 4.2.3...4.2.4