fix: Resolve ca-certificates installed in the local environment

[jjerphan]

Description

Toward resolving conda-forge/mamba-feedstock#362.

Type of Change

• Bugfix
• Feature / enhancement
• CI / Documentation
• Maintenance

Checklist

• My code follows the general style and conventions of the codebase, ensuring consistency
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I have run pre-commit run --all locally in the source folder and confirmed that there are no linter errors.
• I have added tests that prove my fix is effective or that my feature works
• New and existing tests pass locally with my changes

[codecov]

Codecov Report

❌ Patch coverage is 64.28571% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 63.59%. Comparing base (6f11ca2) to head (6750848).

Files with missing lines	Patch %	Lines
libmamba/src/download/downloader.cpp	64.28%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4101      +/-   ##
==========================================
+ Coverage   63.57%   63.59%   +0.01%     
==========================================
  Files         315      315              
  Lines       38562    38572      +10     
  Branches     2950     2951       +1     
==========================================
+ Hits        24517    24529      +12     
+ Misses      13976    13974       -2     
  Partials       69       69              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[Klaim]

This whole block is extracted from get_root_prefix right?

mamba/libmamba/src/api/configuration.cpp

Lines 699 to 706 in 6f11ca2

	// Find the supposed environment prefix of libmamba.
	// `libmamba` is installed at:
	// - `${PREFIX}/lib/libmamba${SHLIB_EXT}` on Unix
	// - `${PREFIX}/Library/bin/libmamba$.dll` on Windows
	const fs::u8path libmamba_env_prefix = fs::weakly_canonical(
	util::on_win ? libmamba_path.parent_path().parent_path().parent_path()
	: libmamba_path.parent_path().parent_path()
	);

I would prefer if you factorize that in a function called here and in get_root_prefix.

Also, I think this is a bit fragile: is that supposed to work with micromamba which can be installed in any place (my micromamba never has ../bin as an example) and doesnt have a libmamba install?

Isnt there an env variable already for the env prefix? Or we really want the one from the executable here?

I see we later check the existence of this path so maybe it's not important and it's Ok with micromamba, just asking to be sure. :)

[jjerphan]

Also, I think this is a bit fragile: is that supposed to work with micromamba which can be installed in any place (my micromamba never has ../bin as an example) and doesnt have a libmamba install?

This is only meant to support a new use-case (see conda-forge/mamba-feedstock#362 (comment)).

Isnt there an env variable already for the env prefix? Or we really want the one from the executable here?

I do not think we can expect that an environment variable is set for the use-case given above.