Ginga detection incorrect when importing

[Universebenzene]

With both ginga(3.4.0) and imexam installed, when I run import imexam, it gives Ginga not installed, use other viewer, or no viewer.

I checked the directories and found the detection returned Error at this line in the ginga.viewer.py. Should the AstropyWCS be change to any of this ones or any other things? Or did I forgot any package installed? Thanks.

[jazamatazz]

I am having this issue as well.