Add new flags to facilitate automated forge

[hadim]

I am trying to setup a private forge with a mix of inter-dependents noarch and arch-specific packages. The setup is similar to https://github.com/prefix-dev/ai-forge/.

The variants file looks like this.

zip_keys:
  - - ${{ "cxx_compiler_version" if unix }}
    - ${{ "c_compiler_version" if unix }}
  - - python
    - numpy
    - python_impl

c_stdlib:
  - ${{ "sysroot" if linux }}
  - ${{ "macosx_deployment_target" if osx }}
  - ${{ "vs" if win }}

c_stdlib_version:
  - ${{ "2.17" if linux }}
  - ${{ "10.13" if osx and x86_64 }}
  - ${{ "11.0" if osx and arm64 }}

c_compiler:
  - ${{ "gcc" if linux }}
  - ${{ "clang" if osx }}
  - ${{ "vs2019" if win and x86_64 }}
  - ${{ "vs2022" if win and arm64 }}

c_compiler_version:
  - ${{ "13" if linux }}
  - ${{ "17" if osx }}

cxx_compiler:
  - ${{ "gxx" if linux }}
  - ${{ "clangxx" if osx }}
  - ${{ "vs2019" if win and x86_64 }}
  - ${{ "vs2022" if win and arm64 }}

cxx_compiler_version:
  - ${{ "13" if linux }}
  - ${{ "17" if osx }}

rust_compiler:
  - rust

rust_compiler_version:
  - 1.80.0

python:
  # part of a zip_keys: python, python_impl, numpy
  - 3.12.* *_cpython
python_impl:
  # part of a zip_keys: python, python_impl, numpy
  - cpython
python_min:
  # minimum supported python version per CFEP-25
  # bump to next minor version when we drop python versions
  - "3.12"

# we build for the oldest version possible of numpy for forward compatibility
# we roughly follow NEP29 in choosing the oldest version
numpy:
  # part of a zip_keys: python, python_impl, numpy
  - 1.26

---

Here are two flags I think could improve the single-repo based way of setting up a forge.

• rattler-build build --no-test-if-emulate:

Do not run tests if target-platform != build-platform. Sometimes a test-time dep is not available on osx-arm64 while the package has been built on osx-64.

• rattler-build build --noarch-platform=linux-64

Only buildnoarch packages if build-platform == noarch-platform (set to linux-64 on c-f for example). It guarantees that at least one platform can build a noarch package (for example, many c-f noarch packages do not work on Windows because of missing pytorch).

That flag could also be something like --skip-noarch but the former one is easier to parametrized in the GHA CI.

[wolfv]

Hi @hadim thank you for the two suggestions. They both make a lot of sense to me. I think both could be achieved with what's there right now:

For building noarch packages only on e.g. linux-64 we could do:

build:
  skip:
      - build_platform != "linux-64"

For skipping tests on emulation we coudl do:

tests:
  - if: build_platform == target_platform
     then: ...

But your suggestions also make total sense to me and we should implement them!

[hadim]

I like your workarounds. Good idea.

But your suggestions also make total sense to me and we should implement them!

I might give it a try at some point then.

[hadim]

closed by #1192 and #1190