A dynamically linkable Python 3.8 is not provided (needed for Samba)

[abartlet]

See https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=22618#c10 and https://bugzilla.samba.org/show_bug.cgi?id=14451

Like some other projects, Samba simply can't be made to compile as a static object so we need a way to link to python3 compatible with dynamic linking.

This didn't show up in Samba's CI because it is the surrounding container that changed.

@douglasbagnall has a proof of concept patch at https://attachments.samba.org/attachment.cgi?id=16153 that changes us back to the system python, but while that would more closely match what is in our CI, that isn't ideal.

[inferno-chromium]

Sure you can remove system python in Dockerfile and match it similarly to your CI. We just provide python 3.8 as latest python for most projects, you should use what works for your CI and install it in Dockerfile and use instrumented version.

[abartlet]

To be clear, it would not be an instrumented python, it would just be the packaged system python as was in place previously. We don't have the resources to start re-building all our dependencies to make them instrumented (sadly). Ideal would be if oss-fuzz could provide common instrumented dependencies, as is done here, but in a way we could use (dynamically linkable), or otherwise not interfere. Was this change (to provide the static-only python 3.8) CI'ed on the oss-fuzz side? Andrew Bartlett

[inferno-chromium]

To be clear, it would not be an instrumented python, it would just be the packaged system python as was in place previously. We don't have the resources to start re-building all our dependencies to make them instrumented (sadly). Ideal would be if oss-fuzz could provide common instrumented dependencies, as is done here, but in a way we could use (dynamically linkable), or otherwise not interfere. Was this change (to provide the static-only python 3.8) CI'ed on the oss-fuzz side? Andrew Bartlett

Since it is a builder docker container change, it cannot be tested in CI. Also, CI can't complete for 300+ projects. CI is just for testing new PR for a particular project. Can you remove the static-only python 3.8 in Dockerfile and then do whatever you want there, we are totally flexible with whatever change you want to do in Dockerfile.