Allow building with cmake on Windows

[gabrieljreed]

Resolves #1321
Resolves #2123

Premise

Path normalization

On Windows, rez applies path normalization (converting forward slashes to back slashes) to any environment variable whose name matches the pattern in the pathed_env_vars config setting, which defaults to *PATH. This is correct behavior for variables like PATH, PYTHONPATH, and LD_LIBRARY_PATH, which need native Windows path separators. However, CMAKE_MODULE_PATH also matches *PATH, but Cmake requires forward slashes in this variable.

Unterminated string literal in rez_install_python

When building rez packages on Windows that use rez_install_python (with nmake), the build fails with a Python SyntaxError: unterminated string literal

File "<string>", line 1
    'import
    ^
SyntaxError: unterminated string literal (detected at line 1)

The root cause is in InstallPython.cmake - the add_custom_command that compiles .py files into .pyc uses single quotes around the Python -c argument.

COMMAND ${py_bin} -c 'import py_compile \; py_compile.compile(...)'

On Unix, make dispatches commands via /bin/sh where single quotes are valid string delimiters. On Windows, nmake dispatches via cmd.exe, where single quotes are literal characters, so Python receives 'import as the start of an unterminated string literal.

Changes

• Add a new configuration setting, non_pathed_env_vars, which is an exclusion list that takes priority over pathed_env_vars.
  • Any variable matching a pattern in this list is except from path normalization, even if it also matches pathed_env_vars
  • Supports the same fnmatch wildcards as pathed_env_vars
  • The default value ships with CMAKE_MODULE_PATH out of the box, since this is a known case where we don't want normalization
• Fix install_python macro
  • Switch from single quoted shell args to cmake double quoted string for the -c argument
  • Add VERBATIM keyword to add_custom_command so Cmake handles all platform-specific argument quoting correctly

Tests

• I'm able to build the hello_world example package on both Windows and Linux after setting build_system = "cmake"
• Add new tests for ActionInterpreter._is_pathed_key and shell.set_env
• I was unable to write tests for the rez_install_python cmake macro, but I verified that it worked manually

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: gabrieljreed / name: Gabriel Reed (8245bc3, b5c0c5c, ce9ff60, d12912b)

[herronelou]

This would also help/fix: #1923 #1909

[maxnbk]

Nicely done contribution.

Apart from this PR, we could use actual tests that use/generate the hello_world package, but I won't consider that a blocker for this particular PR merge.

I made a few suggestions are mostly cosmetic, or affect the way docs generate.

The only open question is the CMAKE_PREFIX_PATH one, or CMAKE_*_PATH, alternatively. I suspect the right thing to do would be the wildcard, since this is a new config value, and if someone needs to override the default config value, the result is effectively the same. I'm not just sure if there are any CMAKE path vars that are supposed to have the same treatment.

[codecov]

Codecov Report

❌ Patch coverage is 66.66667% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 61.29%. Comparing base (5c598c5) to head (f0ba2af).
⚠️ Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
src/rez/rezconfig.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2090   +/-   ##
=======================================
  Coverage   61.29%   61.29%           
=======================================
  Files         164      164           
  Lines       20568    20571    +3     
  Branches     3575     3576    +1     
=======================================
+ Hits        12607    12609    +2     
- Misses       7089     7090    +1     
  Partials      872      872           

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[maxnbk]

The ruff issue was fixed, a rebase will pick it up.

[JeanChristopheMorinPerso]

I think this is almost ready. I left a small comment to enhance the cmake utility a bit more.

[JeanChristopheMorinPerso]

Suggested change

	COMMAND ${py_bin} -c "import py_compile; py_compile.compile('${fabs}', '${local_fc}', None, True)"
	COMMAND ${py_bin} -c "import sys; py_compile; py_compile.compile(sys.argv[1], sys.argv[2], None, True)" ${fabs} ${local_fc}

I think this is safer as it will not fail if the path contains a backslash or a single quote (which I think is valid in Windows).

[gabrieljreed]

This seems good to me, I'm wondering if it shouldn't be import sys; import py_compile; instead of just import sys; py_compile;?

My notes were resolved.

[maxnbk]

My comments were addressed, though @JeanChristopheMorinPerso might want to recheck his.

[JeanChristopheMorinPerso]

Suggested change

	# Takes priority over :data:`pathed_env_vars`.
	# Takes priority over :data:`pathed_env_vars`.
	# .. versionadded:: 3.5.0

[JeanChristopheMorinPerso]

This looks good to me if Stephen is good with it. I'm not a fan of adding a new setting just for that, but if it works, then let's go with it.

@maxnbk Since you're likely going to do the next release, I'm leaving the decision of which version to put in the versionadded sphinx directive.