Testing: Update the packaging tar bz2 and xz tests on windows

[jcbrill]

Rework the windows system tar executable handling in the packaging tar tests for bz2 and xz. Remove test test/packaging/tar/xz_packaging.py from the windows runner skip file.

Changes:

• test/packaging/tar/bz2_packaging.py:
  • Remove searching for and prepending bzip2.exe to the environment path for windows.
  • tar.exe in Windows 10 and GH windows-2022 appears not to support bzip2 compression even when bzip2.exe is on the system path.
  • tar.exe in Windows 11 and GH windows-2025 appears to support bzip2 compression without any additions to the system path.
  • If the candidate tar.exe is the windows system tar.exe, check the version string for bz2lib support.
• test/packaging/tar/xz_packaging.py:
  • Remove searching for and prepending xz.exe to the environment path for windows.
  • tar.exe in Windows 10 and GH windows-2022 appears not to support xz compression even when xz.exe is on the system path.
  • tar.exe in Windows 11 and GH windows-2025 appears to support xz compression without any additions to the system path.
  • If the candidate tar.exe is the windows system tar.exe, check the version string for liblzma support.
• Remove test/packaging/tar/xz_packaging.py from the windows ci test skip file.

As of 06-Jul-2025:

• The packaging tar tests for bz2 and xz are skipped in GH windows-2022.
• The packaging tar tests for bz2 and xz are run in GH windows-2025.

Contributor Checklist:

• I have created a new test or updated the unit tests to cover the new/changed functionality.
• I have updated CHANGES.txt and RELEASE.txt (and read the README.rst).
• I have updated the appropriate documentation

[bdbaddog]

Are you ignoring the git tar? Which could be used in the case where the windows tar doesn't support bz2?

[jcbrill]

It shouldn't.

When either os.environ["SystemRoot"] or os.environ["windir"] is defined:

• The test is performed if the tar.exe is not %SystemRoot%/system32/tar.exe.
• The test may be performed if the tar.exe is %SystemRoot%/system32/tar.exe subject to the version string check.

One of these two environment variables should be defined.

If neither variables are defined, then the "--version" string is inspected for bsdtar, - libarchive and other fields. If there is not a match for the known fields, then the test is performed.

It should be unlikely that a bsdtar executable is used when the two Windows system environment variables are undefined.

[jcbrill]

Which could be used in the case where the windows tar doesn't support bz2?

The test, as written prior to changes, only checks the first tar executable found on the path.

[jcbrill]

Locally annotated change (not pushed yet)

        windir = os.environ.get("SystemRoot")
        if not windir:
            windir = os.environ.get("windir")
        if not windir:  # <== ADDED
            windir = os.path.join(os.environ.get("SystemDrive", "C:") + os.path.sep, "Windows")  # <== ADDED
        expected = os.path.normcase(os.path.abspath(os.path.join(windir, "System32", "tar.exe")))
        if tar != expected:
            return False

Additional clause added to always test the target executable path against what should be the windows system32 path.

[bdbaddog]

Isn't windir always defined on windows?

[jcbrill]

It should be.

Depends on your level of paranoia:

(3.12.9) S:\SCons\Test-WinSkip>type test-env.bat
@setlocal
@python -c "import os; print([os.environ.get(var) for var in ['SystemDrive', 'SystemRoot', 'windir']])"
@set SystemDrive=
@set SystemRoot=
@set windir=
@python -c "import os; print([os.environ.get(var) for var in ['SystemDrive', 'SystemRoot', 'windir']])"
@endlocal

(3.12.9) S:\SCons\Test-WinSkip>test-env
['C:', 'C:\\Windows', 'C:\\Windows']
[None, None, None]

[bdbaddog]

Probable makes sense to move this logic into TestSCons?

[jcbrill]

After copy/pasting/modifying from the xz source code it seemed like it would be a good idea to have only one parameterized implementation.

Wasn't sure where or what name to use.

[jcbrill]

Updated to move common windows system tar code in bz2 and xz scripts to a private common module in the packaging/tar folder.

It should be easier now to move somewhere else if desired. At present, only used in two places.

[jcbrill]

Well that didn't work as I had hoped. The source file test/packaging/tar/_windows_tar.py was "run" as a test (which passes) which is undesirable.

Seems unfortunate to have to add to TestSCons for two tests.

[bdbaddog]

You can exclude _windows_tar.py , see: https://github.com/SCons/scons/wiki/DevGuide-TestingMethodology#selecting-tests

[bdbaddog]

Good enough. Merging.

[jcbrill]

@bdbaddog Did you see the last commit about a minute before the merge?

[bdbaddog]

@bdbaddog Did you see the last commit about a minute before the merge?

The TestSConsTar.py.. Yes.

At this point, enough CPU cycles spent for this issue. Seems good enough and merged.