virtualenv/pip and LDFLAGS

[Greg Troxel <gdt%lexort.com@localhost>]

I'm using virtualenv (from pkgsrc) to create a python venv, and then
using pip (in the venv) to install stuff, for Home Assistant.  This is
mostly ok.

A wrinkle is that I am using NetBSD 9 but gcc10 because so many things
are not ok with 7.

I found that some modules referenced /usr/lib/libstdc++.so.9, instead of
gcc10's version.  I rebuilt pkgsrc dependencies and re-did pip install
(after clearing cache) and mostly fixed that, to have my HA world be
100% gcc10.

When building pysilero-vad, it ends up finding base libstdc++ instead,
and I think this is because the build line ends up with -L/usr/lib
-Wl,-rpath,/usr/lib and this is preferred to the system lib.

Arguably this is a bug in something in pip, and also a bug in gcc which
should refuse to find other than its own libstdc++.  If I hand-edit the
build line to remove and re-run it, the resulting .so is ok.

pysilero-vad uses c++20 but it's ok with gcc10, I think, vs gcc12 that
one needs in general.  I'm kludging my builds to 10.

I just pushed a package to wip, which builds ok on NetBSD 10 amd64 and
NetBSD 9 amd64.


Does anyone know if it is pip in venv, or ? that  is inserting the
-L/usr/lib and how to stop it?