A quick look at NixOS on distrowatch and it looks like you get a Gimp 2.10.38 - Is that correct ?
it also shows default python packages as Python 3.xx
Gimp python plugins require Python 2.7 + a gimp-python package and these are missing from most up-to-date Gimp installations.
As a check, in the filters menu is there a Python-Fu entry ?
If not then python plugins do not work. There are alternatives where Python 2.7 is bundled with Gimp 2.10 to enable python plugins. The flatpak version, also some of the appimage Gimps.
I am packing in for the day now but if you post details you will get more advice.
(edit - not looking promising
Nix stores all packages in isolation from each other; as a result there are no /bin, /sbin, /lib or /usr directories and all packages are kept in /nix/store instead.}
it also shows default python packages as Python 3.xx
Gimp python plugins require Python 2.7 + a gimp-python package and these are missing from most up-to-date Gimp installations.
As a check, in the filters menu is there a Python-Fu entry ?
If not then python plugins do not work. There are alternatives where Python 2.7 is bundled with Gimp 2.10 to enable python plugins. The flatpak version, also some of the appimage Gimps.
I am packing in for the day now but if you post details you will get more advice.
(edit - not looking promising
Nix stores all packages in isolation from each other; as a result there are no /bin, /sbin, /lib or /usr directories and all packages are kept in /nix/store instead.}