[libcamera-devel] ninja build breaks out of venv

[Kieran Bingham]

Hi Brian,

Quoting Brian Olson (2021-12-05 13:05:42)
> $ ninja -C build install
> ...
> /usr/bin/python3
> /blah/blah/blah/libcamera/utils/tracepoints/./gen-tp-header.py ...
> Traceback (most recent call last):
>   File "/blah/blah/blah/libcamera/utils/tracepoints/./gen-tp-header.py",
> line 10, in <module>
>     import jinja2
> ModuleNotFoundError: No module named 'jinja2'
> 
> Yeah, I don't have it installed at the root level, but I have jinja2
> installed in the venv I was running ninja from. I don't know how to say
> "use this python3" other than putting it in the PATH, which it was, but
> ninja ignored that and went with /usr/bin/python3, and that failed.


The only thing I can imagine is happening here, is that meson is
'breaking' out of the venv when calling install. I believe meson uses
pkexec or such to elevate to root prividiges when installing. I can only
assume that this 'escapes' the venv, by not keeping environment
variables.

As this is a meson bug, it's probably something to report over at:

https://github.com/mesonbuild/meson/issues

A quick search on venv there brings up:

- Wrong install_path generated by python module for virtual environment interpreter
  https://github.com/mesonbuild/meson/issues/7623

Which might be related, so worth referencing if you create a new issue
there.

If you'd prefer us to log that bug, let me know and I'll try to post
something, but it might be better coming from you as you have the issue
at hand and can replicate it, while I do not use venvs I'm afraid.

--
Kieran