I was tearing my hair out trying to find why the rendering in gv and every other ghostscript-based PDF viewer had come to be entirely unreadable on my laptop It's fine on my desktop machine at work. Same versions of all the font packages, ghostscript itself, and viewers.

Finally, I ran "dpkg --get-selections | grep font" to see what I might have different. Then, I said "apt-get install psfontmgr", which upgraded from version 0.11.0 to 0.11.1, and all is well again. If you're not happy with how troff output looks in ghostscript, maybe you have the same problem.

It seems as if we might get a partial fix for the next Glibc thread library breaking every existing exception-safe and thread-safe C++ library. There's no sound reason to break them at all, but reason doesn't seem to figure.