libplacebo @7.349.0_0: ModuleNotFoundError: No module named 'jinja2'

[ShadSterling (Shad Sterling)]

2018 Intel macbook just upgraded to Sequoia, attempting to migrate ports.

mpv can't install because its dependency libplacebo fails with this and several similar errors:

:info:build [1/52] /opt/local/bin/meson --internal exe --unpickle /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_libplacebo/libplacebo/work/build/meson-private/meson_exe_python3.12_c9bf29496c5c4e48bd7a306095ba2fc6023a38a2.
dat
:info:build FAILED: src/renderer.c
:info:build /opt/local/bin/meson --internal exe --unpickle /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_libplacebo/libplacebo/work/build/meson-private/meson_exe_python3.12_c9bf29496c5c4e48bd7a306095ba2fc6023a38a2.dat
:info:build while executing ['/opt/local/Library/Frameworks/Python.framework/Versions/3.12/bin/python3.12', '/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_libplacebo/libplacebo/work/libplacebo-7.349.0/tools/glsl_preproc/m
ain.py', '../libplacebo-7.349.0/src/renderer.c', 'src/renderer.c']
:info:build --- stdout ---
:info:build --- stderr ---
:info:build /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_libplacebo/libplacebo/work/libplacebo-7.349.0/tools/glsl_preproc/macros.py:87: SyntaxWarning: invalid escape sequence '\s'
:info:build   line = re.sub(f'^\s{{1,{leading_spaces}}}', '', line)
:info:build Traceback (most recent call last):
:info:build   File "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_libplacebo/libplacebo/work/libplacebo-7.349.0/tools/glsl_preproc/main.py", line 6, in <module>
:info:build     from macros import Macro
:info:build   File "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_libplacebo/libplacebo/work/libplacebo-7.349.0/tools/glsl_preproc/macros.py", line 6, in <module>
:info:build     from templates import *
:info:build   File "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_libplacebo/libplacebo/work/libplacebo-7.349.0/tools/glsl_preproc/templates.py", line 1, in <module>
:info:build     import jinja2
:info:build ModuleNotFoundError: No module named 'jinja2'

Giving mpv a different python variant doesn't seem to have any effect; libplacebo seems to use 3.12 independent of mpv