The Ubuntu 20.04 image on GitHub Actions will be unavailable by
2025-04-15. See <https://github.com/actions/runner-images/issues/11101>
for more information on the deprecation and removal.
Therefore all build jobs that use the Ubuntu 20.04 runner image
of GHA have to be either migrated to a newer runner image (if
the compiler version is available on a newer image) or have to be
moved to Docker containers using Ubuntu 20.04 (if the compiler
version is not available on the newer runner images).
This is yet another workaround for hanging posix-cmake-test on Mac OS.
This enables parallel builds again, but uses Ninja build system instead
of Makefiles. Enabling parallel builds speeds up the build process and
releases Mac OS builders for other jobs sooner.
Additionally, fix incorrect apt invocations in CMake-related jobs. apt
is supposed to be used in interactive shells, and in scripts apt-get is
recommended. Also, apt-get update is needed before apt install, and
matrix.install must be transformed to a space-separated list. Also added
retries on network errors.
Properly set BUILD_JOBS environment variable in CMake-related jobs as
it is used in build and run steps. Without the variable being set, -j
without a number means "no limit on the number of jobs", which may
hit system resource limits and cause the job to fail.
Also, Mac OS seem to sometimes hang on too many parallel build jobs,
even if BUILD_JOBS is specified correctly. So disable parallel builds
for now.
Additionally, use GIT_FETCH_JOBS universally.
- Added clang-15 jobs.
- Added C++23 testing for gcc and clang on Linux.
- Updated clang version for UBSAN job.
- Removed clang-12 libc++ job - libc++ is now tested with clang-15.
- Updated Ubuntu version for clang jobs to avoid having to use external APT
repository.
- Updated python package installation for compatibility with Ubuntu 22.04.
In Ubuntu 20.04 there appeared an updated version of the
software-properties-common package in focal-updates, which ships a newer
apt-add-repository version that doesn't support -P/-S/-U command line arguments.
Since we cannot rely on package version checks to determine apt-add-repository
capabilities, we have to parse its --help output instead.
Also, made source list processing more protected against spaces.
