libcxx v19.1.0

[regro-cf-autotick-bot]

It is very likely that the current package version for this feedstock is out of date.

Checklist before merging this PR:

• Dependencies have been updated if changed: see upstream
• Tests have passed
• Updated license if changed and license_file is packaged

Information about this PR:

1. Feel free to push to the bot's branch to update this PR if needed.
2. The bot will almost always only open one PR per version.
3. The bot will stop issuing PRs if more than 3 version bump PRs generated by the bot are open. If you don't want to package a particular version please close the PR.
4. If you want these PRs to be merged automatically, make an issue with @conda-forge-admin,please add bot automerge in the title and merge the resulting PR. This command will add our bot automerge feature to your feedstock.
5. If this PR was opened in error or needs to be updated please add the bot-rerun label to this PR. The bot will close this PR and schedule another one. If you do not have permissions to add this label, you can use the phrase @conda-forge-admin, please rerun bot in a PR comment to have the conda-forge-admin add it for you.

Pending Dependency Version Updates

Here is a list of all the pending dependency version updates for this repo. Please double check all dependencies before merging.

Name	Upstream Version	Current Version
clangdev	19.1.0
libcxx	19.1.0
llvmdev	19.1.0

_{This PR was created by the regro-cf-autotick-bot. The regro-cf-autotick-bot is a service to automatically track the dependency graph, migrate packages, and propose package version updates for conda-forge. Feel free to drop us a line if there are any issues! This PR was generated by - please use this URL for debugging.}

[conda-forge-webservices]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe/meta.yaml) and found it was in an excellent condition.

[h-vetinari]

@conda-forge/libcxx, this is ready now, PTAL!

The main changes are that we're shipping with basic tzdb-support (not full yet because we can't patch the static lib), plus libcxx 19 started shipping C++20 modules. For more details see #142 / #178

[h-vetinari]

Sorry for the relatively short ping cadence, but given how much of the LLVM stack depends on this (i.e. clangdev + children), I'd appreciate if you could give this a quick look-over @isuruf. All the big changes were discussed in #178 already, there shouldn't be any surprises IMO.

[isuruf]

Thanks

[h-vetinari]

@beckermr, any idea why the downstream tests are still failing package validation here despite conda-forge/conda-forge-ci-setup-feedstock#344?

validation results:
{
  "osx-64/libcxx-testing-0.18.99-h33f3928_1.conda": false,
  "osx-64/libcxx-testing-0.16.99-he7e073f_1.conda": false,
  "osx-64/libcxx-devel-19.1.0-h7c275be_0.conda": true,
  "osx-64/libcxx-19.1.0-hf95d169_0.conda": true,
  "osx-64/libcxx-testing-0.17.99-ha468150_1.conda": false
}
NOTE: Any outputs marked as False are not allowed for this feedstock. See https://conda-forge.org/docs/maintainer/infrastructure/#output-validation-and-feedstock-tokens for information on how to address this error.

libcxx-testing aren't built here, just downstream tests