That doesn't say much, because `guix environment` provides little
isolation. You might try with pure environments, but the better way of
replicating the build environment is using `-K`.
Ran in a `guix environment --pure --container` and it still built successfully.
I have yet to look at your package definition (pardon me), but do you
notice anything strange between the Makefiles you generate on your own
vs. the Makefiles you generate in `guix build`?
Thanks for the idea. Made me realise that I could run the build steps on my own in the /tmp/ folders `guix build` generates with `--keep-failed`. And in doing so I got it to build even there. Figured that it then has to be some difference in the build steps and have now figured out that it is the flag "-DCMAKE_BUILD_TYPE=RelWithDebInfo" that is causing the issue. If I changed that to `Release` instead of `RelWithDebInfo` then the package builds successfully. And it also has plugins now!
I will return with a revised version later. First I will try to package libpsd, an optional dependency of Nomacs.