enhance PythonPackage and PythonBundle easyblocks to add support to install dummy Python packages

[lexming]

This PR adds a new dummy_package option to PythonPackage and PythonBundle that allows to install any python package as a dummy package, which is a fake installation that makes package managers believe that the package is installed.

In practice, this does the following:

• sources of the dummy python package are not fetched or extracted
• the usual build/installation of the python package does not happen
• EB creates a dist-info folder in the site-packages directory with just a minimal METADATA file that contains the name and version of the package

The purpose of dummy packages is to be able to fulfill harcoded requirements in wheels that target python packages repackaging libraries that are already available in EasyBuild. The most notorious example are the CUDA libraries, wheels with support for CUDA need a collection of wheels from Nvidia that just repackage the CUDA libraries. Therefore, with this PR we can depend on the CUDA easyconfig as usual, while still have the fake cuda python packages to not break pip check.

Easyconfig using this feature in easybuilders/easybuild-easyconfigs#25266

[lexming]

Test report in easybuilders/easybuild-easyconfigs#25266 (comment)

[pavelToman]

Works fine for me in PR:

• {bio}[foss/2024a] Rapids-SingleCell v0.10.11, RAPIDS v24.10.0, ucx-py v0.40.00, update CUDA-Python v12.6.2.post1 w/ CUDA 12.6.0 easybuild-easyconfigs#25558

[boegel]

@boegelbot please test @ jsc-zen3
EB_ARGS="--installpath /tmp/$USER/pr4063 Python-3.11.3-GCCcore-12.3.0.eb Python-3.14.2-GCCcore-15.2.0.eb Python-bundle-PyPI-2025.07-GCCcore-14.3.0.eb matplotlib-3.10.5-gfbf-2025b.eb tqdm-4.67.1-GCCcore-14.3.0.eb"

[boegelbot]

@boegel: Request for testing this PR well received on jsczen3l1.int.jsc-zen3.fz-juelich.de

PR test command 'if [[ develop != 'develop' ]]; then EB_BRANCH=develop ./easybuild_develop.sh 2> /dev/null 1>&2; EB_PREFIX=/home/boegelbot/easybuild/develop source init_env_easybuild_develop.sh; fi; EB_PR=4063 EB_ARGS="--installpath /tmp/$USER/pr4063 Python-3.11.3-GCCcore-12.3.0.eb Python-3.14.2-GCCcore-15.2.0.eb Python-bundle-PyPI-2025.07-GCCcore-14.3.0.eb matplotlib-3.10.5-gfbf-2025b.eb tqdm-4.67.1-GCCcore-14.3.0.eb" EB_CONTAINER= EB_REPO=easybuild-easyblocks EB_BRANCH=develop /opt/software/slurm/bin/sbatch --job-name test_PR_4063 --ntasks=8 ~/boegelbot/eb_from_pr_upload_jsc-zen3.sh' executed!

• exit code: 0
• output:

Submitted batch job 10097

Test results coming soon (I hope)...

Details

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Message to humans: this is just bookkeeping information for me,
it is of no use to you (unless you think I have a bug, which I don't).

[boegel]

✅ retested use of dummy_package custom easyconfig parameter via:

• {lib}[gompi/2025a] CUDA-wheel-bundle v12.8.0 w/ CUDA 12.8.0 easybuild-easyconfigs#25266

[boegelbot]

Test report by @boegelbot

Overview of tested easyconfigs (in order)

• SUCCESS Python-3.11.3-GCCcore-12.3.0.eb

• SUCCESS Python-3.14.2-GCCcore-15.2.0.eb

• SUCCESS Python-bundle-PyPI-2025.07-GCCcore-14.3.0.eb

• SUCCESS matplotlib-3.10.5-gfbf-2025b.eb

• SUCCESS tqdm-4.67.1-GCCcore-14.3.0.eb

Build succeeded for 5 out of 5 (total: 3 hours 2 mins 32 secs) (5 easyconfigs in total)
jsczen3c3.int.jsc-zen3.fz-juelich.de - Linux Rocky Linux 9.7, x86_64, AMD EPYC-Milan Processor (zen3), Python 3.9.25
See https://gist.github.com/boegelbot/13b42af0ff95e230aad86e50d6b06572 for a full test report.

[boegel]

Test report by @boegel

Overview of tested easyconfigs (in order)

• SUCCESS Python-bundle-PyPI-2024.06-GCCcore-13.3.0.eb

• SUCCESS SciPy-bundle-2025.07-gfbf-2025b.eb

• SUCCESS Pillow-11.3.0-GCCcore-14.3.0.eb

• SUCCESS hypothesis-6.90.0-GCCcore-13.2.0.eb

• SUCCESS zlib-ng-2.2.4-GCCcore-14.2.0.eb

• SUCCESS statsmodels-0.14.5-gfbf-2025a.eb

Build succeeded for 6 out of 6 (total: 4 hours 38 mins 59 secs) (6 easyconfigs in total)
node4217.shinx.os - Linux RHEL 9.6, x86_64, AMD EPYC 9654 96-Core Processor (zen4), Python 3.9.21
See https://gist.github.com/boegel/c077bdf9a6b755f84a3f5c51324b5199 for a full test report.