[bug] Equals sign (`=`) in profile (package) pattern broken

[stevenwdv]

Describe the bug

An equals sign (=) in a profile (package) pattern causes issues, because conan splits the key and value in the wrong place:

conan/conan/internal/model/conf.py

Lines 726 to 727 in 8bdbf02

	for op, method in ConfDefinition.actions:
	tokens = line.split(op, 1)

How to reproduce it

Given this profile:

[conf]
qt/[>=6.9]:tools.cmake.cmaketoolchain:extra_variables={'QT_NO_APPLE_SDK_AND_XCODE_CHECK': 'ON'}

Conan fails with the following error:

ERROR: Error reading './conan_profile' profile: [conf] 'qt/[>' not allowed in profiles

Conan splits the line as:
qt/[> = 6.9]:tools.cmake.cmaketoolchain:extra_variables={'QT_NO_APPLE_SDK_AND_XCODE_CHECK': 'ON'}

instead of
qt/[>=6.9]:tools.cmake.cmaketoolchain:extra_variables = {'QT_NO_APPLE_SDK_AND_XCODE_CHECK': 'ON'}

[AbrilRBS]

Hi @stevenwdv thanks a lot for taking the time to submit this issue.

As far as I can tell, this would not be a bug, but expected behaviour. The profile patterns do not allow for version range matching as it currently stands (I'll check with the team if this is something we'd like to consider for future versions), and it currently only understands * in the different reference fields. What's your use-case for defining these for different versions? The condition should be known beforehand (unless an override happens I guess?)

Let me know if this helps clear things up :)

[stevenwdv]

@AbrilRBS Thanks for responding!

As far as I can tell, this would not be a bug, but expected behaviour. The profile patterns do not allow for version range matching as it currently stands

Oh, whoops. I changed it to qt/[^6.9] because it's close enough, but I guess that this won't work then... That's kinda confusing; I'd really like a warning when version ranges are used in a context where they're not supported, and maybe some docs clarification.

What's your use-case for defining these for different versions?

Defining CMake variables specific for one version. In this case, I know that Qt 6.9 will break unless I don't pass a specific variable, but maybe I should just pass it unconditionally. (But that does have a small disadvantage for now, see https://qt-project.atlassian.net/browse/QTBUG-138427 only if you're really interested.)

I can think of other usecases where some variable or macro may be needed in an old version, but where a new version doesn't need it anymore because of a fix.

Other usecases may be options specific to one package version. Or are version ranges supported for [options]?

[AbrilRBS]

I'd really like a warning when version ranges are used in a context where they're not supported

I'm checking if a warning/error for this would be possible, as it currently stands, using version ranges (that don't trigger your miss-split with an = sign) are simply ignored, and I think it might be worth it to alert the user in such cases.

Regardless of if this warning is added, I'll be updating the documentation to better reflect that version ranges are not expected here