...
Now can anyone suggest a fix here? So far the only thing I've seen
explicitly suggested is to patch and recompile lots of stuff most of
whose internals I don't know the first thing about, and the vague
implication that I should blow the whole system away and reinstall it
after (finding out how and) changing my Windows username. I'd much
rather avoid either of those, especially as the latter will cause
data loss. Obviously the contents of the home directory could be
copied out but there's a ton of changes made to assorted other files,
such as /etc/profile, crontab entries, and so on. There's also the
sheer magnitude of the download.