mentioning wheel in pypi install docs

[aiqc]

It would be helpful to mention that wheel is required for the non-legacy install w pypi:
https://pysam.readthedocs.io/en/latest/installation.html#pypi-installation

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Here is an install attempt on a fresh venv with/ without wheel:

^ let it run for ~3min then killed it

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Recreated venv, installed wheel, and retried:

[FionaMoon]

Hi,
I also met this problem when I try to install pysam.
When I try to install pysam directly by pip install pysam:

error: legacy-install-failure

× Encountered error while trying to install package.
╰─> pysam

note: This is an issue with the package mentioned above, not pip.
hint: See above for output from the failure.

I'll try to install wheel as you say to see whether this problem can be solved.
Thank you!

[pettyalex]

One way to fix this would be to move to pyproject.toml, which allows projects to specify that they need wheel at install time: https://pip.pypa.io/en/stable/reference/build-system/pyproject-toml/

[jmarshall]

I think typically wheel will already be installed, and in any case the O.P.'s Installation would likely have eventually succeeded in building from source if he had let it continue. Anyway, I've added a note about wheels vs sdists.

We do now use a pyproject.toml file, but I expect once pip has downloaded the sdist to see it, it will be committed to building from the sdist and will not go back to try a wheel instead. So updating the documentation now that wheels are commonplace suffices.