Address minor lints in gpMgmt build

[bradfordb-vmware]

• use $(PYTHON) as determined by configure instead of relying on python3 being on the path
• use $(libdir) instead of $(prefix)/lib

Authored-by: Bradford D. Boyle [email protected]

[dkrieger-pvtl]

As for renaming python3 to $(PYTHON), I thought python3 is the official executable name that will be installed on all systems; why would we want to allow it to be modified?

@jmcatamney has a lot of context here.

[d]

As for renaming python3 to $(PYTHON), I thought python3 is the official executable name that will be installed on all systems; why would we want to allow it to be modified?

There's no guarantee that "the first thing we find on the path called python3" is even the desirable python (more importantly, it's likely not where you want to search for your dependencies). Typical scenario: /usr/bin/python3 being Python 3.4, but developer wants to build pl/Python using Python 3.9. She would do ./configure /* flags */ PYTHON=/usr/bin/python3.9.

@bradfordb-vmware is that what inspired this change?

[dkrieger-pvtl]

There's no guarantee that "the first thing we find on the path called python3" is even the desirable python (more importantly, it's likely not where you want to search for your dependencies).

I see; this PR is about building the python3 dependencies that we will run with. Then it likely makes sense...this is a pre-install-time action so we need to "bootstrap" to build our dependencies. Once installed, we currently use the PATH/PYTHONPATH to resolve which Python to call via /usr/bin/env python3.

There is currently an effort going on to define the execution environment for Python scripts(e.g. CM utilities).

Note that our general non-python execution environment also works this way; that is gpstart is found via essentially /usr/bin/env gpstart, e.g the gpstart that is resolved by the shell.

[ashwinstar]

@bradfordb-vmware this PR is sitting in draft status for more than a year. Any plans to bring it to prime-time or no more issue on newer versions and can be closed?

[bradfordb-vmware]

@ashwinstar Sorry, this sort of fell of my radar. It looks like there is a merge conflict now so I'll rebase, retest, and move to ready to review.

[ashwinstar]

@ashwinstar Sorry, this sort of fell of my radar. It looks like there is a merge conflict now so I'll rebase, retest, and move to ready to review.

@bradfordb-vmware I believe you fixed all the conflicts and this might be ready to be merged