Fix building PyTorch when using setup.py as the build command

[Flamefire]

When changing use_pip after PythonPackage.__init__ called determine_install_command the change is not honored. Call it again after the change.

This also requires to make it idempotent so all member variables changed in that function need to be set in all cases.

Fixes #3570

[boegel]

lgtm

[boegel]

Test report by @boegel

Overview of tested easyconfigs (in order)

• FAIL (build issue) PyTorch-2.1.2-foss-2023a.eb (partial log available at https://gist.github.com/boegel/27e685051b168584090f717b63425ae0)

Build succeeded for 0 out of 1 (1 easyconfigs in total)
node3540.doduo.os - Linux RHEL 8.8, x86_64, AMD EPYC 7552 48-Core Processor (zen2), Python 3.6.8
See https://gist.github.com/boegel/1b4f4b8f962d2734aa34648a26739cdb for a full test report.

[boegel]

PyTorch test failed in test step with:

10 test failures, 0 test errors (out of 201674)

I was also testing with the wrong easyconfig, because PyTorch-2.1.2-foss-2023a.eb doesn't set buildcmd, but PyTorch-2.1.2-foss-2023b.eb (foss/2023b toolchain instead of foss/2023a) does...

[boegel]

@boegelbot please test @ jsc-zen3
EB_ARGS="PyTorch-2.1.2-foss-2023b.eb"
EB_BRANCH=5.0.x
CORE_CNT=16

[boegelbot]

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

PR test command 'if [[ "5.0.x" != 'develop' ]]; then EB_BRANCH="5.0.x" ./easybuild_develop.sh 2> /dev/null 1>&2; EB_PREFIX=/home/boegelbot/easybuild/"5.0.x" source init_env_easybuild_develop.sh; fi; EB_PR=3574 EB_ARGS="PyTorch-2.1.2-foss-2023b.eb" EB_REPO=easybuild-easyblocks EB_BRANCH="5.0.x" /opt/software/slurm/bin/sbatch --job-name test_PR_3574 --ntasks="16" ~/boegelbot/eb_from_pr_upload_jsc-zen3.sh' executed!

• exit code: 0
• output:

Submitted batch job 5760

Test results coming soon (I hope)...

Details

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[boegel]

Test report by @boegel

Overview of tested easyconfigs (in order)

• SUCCESS vsc-mympirun-5.4.0.eb
• SUCCESS PySide2-5.14.2.3-GCCcore-10.2.0.eb

Build succeeded for 2 out of 2 (2 easyconfigs in total)
node3540.doduo.os - Linux RHEL 8.8, x86_64, AMD EPYC 7552 48-Core Processor (zen2), Python 3.6.8
See https://gist.github.com/boegel/525f263317df61269c129045c000096a for a full test report.

[boegelbot]

Test report by @boegelbot

Overview of tested easyconfigs (in order)

• SUCCESS PyTorch-2.1.2-foss-2023b.eb

Build succeeded for 1 out of 1 (1 easyconfigs in total)
jsczen3c1.int.jsc-zen3.fz-juelich.de - Linux Rocky Linux 9.5, x86_64, AMD EPYC-Milan Processor (zen3), Python 3.9.21
See https://gist.github.com/boegelbot/78c745de1eba89c3649042cbe4f1fb37 for a full test report.