[tex-live] texdoc question

[Joel C. Salomon]

What is the mechanism that TeXdoc uses to open (say) PDF files with
the system default viewer?  On my Ubuntu system, this has stopped
working, instead opening with Nautilus (the file manage) the directory
in which the PDF file lives.

This is *not* a texdoc bug -- other programs have developed this issue
as well.  I'm just not able to report the bug to the right people
until I learn what TeXdoc is expecting.

Any help?

Thanks,
--Joel