[bug] Unable to use "specific names" as values for conf entries

[mhabibav]

Environment details

• Operating System+version: Irrelevant
• Compiler+version: Irrelevant
• Conan version: 2.0.17 (packaged as exe with the pyinstaller script)
• Python version: 3.12

Steps to reproduce

1. In any recipe, setting a conf value to any of the following values results in an error: [copy, re, fnmatch, OrderedDict]. This is probably because there are modules / types with the same name imported in the file where eval is run. That results in the value being interpreted as something other than a string.

Dummy scenario:
conanfile.py

from conan import ConanFile


class dummy(ConanFile):
    name = "fixed_name"
    version = "1.2.3"

    def build(self):
        x = self.conf.get("user.company.conf:conf")
        self.output.warning("|" * 100)
        self.output.warning(type(x))
        self.output.warning(x)
        self.output.warning("|" * 100)

command:

conan build . -c "user.company.conf:conf=fnmatch"

Logs

PS C:\E\ws\temp\New folder (3)> conan build . -c "user.company.conf:conf=re"
ERROR: It's not possible to compose module values and str ones.
PS C:\E\ws\temp\New folder (3)> conan build . -c "user.company.conf:conf=OrderedDict"
ERROR: It's not possible to compose type values and str ones.
PS C:\E\ws\temp\New folder (3)> conan build . -c "user.company.conf:conf=fnmatch"
ERROR: It's not possible to compose module values and str ones.

[mhabibav]

The suspected file where this issue is present is probably: conans/model/conf.py
Particularly the function _get_evaluated_value(__v) in line: 643 (or line 653 in the current version)

[memsharded]

Thanks very much for your report @mhabibav

This is indeed a gap in the evaluation of confs, it didn't take into account the possibility of a match with an existing Python module. I am submitting a fix in #15779 for next 2.2 release.

[mhabibav]

Thanks for the quick fix.

[memsharded]

#15779 merged, it will be in next 2.2