The newly added viewport compositor was missing a try-catch guard around
the OCIO `getProcessor` call. All prior call sites were protected except
this one. Unhandled exceptions can occur if the user tries to use a
colorspace config that is not present in their OCIO configuration.
The surrounding code paths need some work in order to not crash at a
later point, which would also impact builds with no OCIO support at all.
In the case of no OCIO support at all, a warning label is placed on the
node as well.
Pull Request: https://projects.blender.org/blender/blender/pulls/125526
69154a5e3b