The vote to close on that question came from a moderator other than I, but I agree with it.
The reason is your answer there:
I'm one of the maintainers for the solaris project. I tried to
reproduce your error in my environment but could not.
If you open an issue in the solaris github
repo with the full traceback, and
your python/solaris/pyproj/fiona versions, then we would be happy to
try to figure out what's going on.
You, as one of the maintainers for the solaris project, have said that it is appropriate to submit as a bug to the solaris GitHub, and we have a custom close reason here (the one that was used) for closing such questions.
I think that custom close reason was last discussed here at Adding 'bug reports' to off-topic close reasons dialog?