libepoxy @1.5.10 +python39 uses wrong python executable

[ballapete (Peter "Pete" Dyballa)]

Executing:  cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_nue.de.rsync.macports.org_macports_release_tarballs_ports_graphics_libepoxy/libepoxy/work/build" && /opt/local/bin/ninja -j1 -v 
DEBUG: system:  cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_nue.de.rsync.macports.org_macports_release_tarballs_ports_graphics_libepoxy/libepoxy/work/build" && /opt/local/bin/ninja -j1 -v 
[1/35] /opt/local/var/macports/build/_opt_local_var_macports_sources_nue.de.rsync.macports.org_macports_release_tarballs_ports_graphics_libepoxy/libepoxy/work/anholt-libepoxy-70a20c6/src/gen_dispatch.py --header --no-source --outputdir=include/epoxy ../anholt-libepoxy-70a20c6/registry/gl.xml
FAILED: include/epoxy/gl_generated.h 
/opt/local/var/macports/build/_opt_local_var_macports_sources_nue.de.rsync.macports.org_macports_release_tarballs_ports_graphics_libepoxy/libepoxy/work/anholt-libepoxy-70a20c6/src/gen_dispatch.py --header --no-source --outputdir=include/epoxy ../anholt-libepoxy-70a20c6/registry/gl.xml
/bin/sh: /opt/local/var/macports/build/_opt_local_var_macports_sources_nue.de.rsync.macports.org_macports_release_tarballs_ports_graphics_libepoxy/libepoxy/work/anholt-libepoxy-70a20c6/src/gen_dispatch.py: /opt/local/bin/python3.10: bad interpreter: No such file or directory
ninja: build stopped: subcommand failed.
Command failed:  cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_nue.de.rsync.macports.org_macports_release_tarballs_ports_graphics_libepoxy/libepoxy/work/build" && /opt/local/bin/ninja -j1 -v 

Indeed I am on Python 3.9, and since so many ports do not support Python 3.10 it makes no sense to install it.

Obviously Portfile is faulty because the variant python39 does not have a line

set python_vers         3.9

which is needed in the post-patch clause. Adding it let's gen_dispatch.py perform its work and build libepoxy.

Besides: What's so wrong with line

#!/usr/bin/env python3

which starts the script gen_dispatch.py?

[ballapete (Peter "Pete" Dyballa)]

Main.log from PPC Tiger, Mac OS X 10.4.11

[jmroot (Joshua Root)]

In c8e0578e294da39f4b107aebb9927dfc672b3be6/macports-ports (master):

libepoxy: remove python variants, just use 3.10

Fixes: #65186