And did a "make" and "make install" . Bad idea!!! It trashed my 5.10.0 install and now all my printing via hplib is broken, among other things. Assuming I can revert to 5.10.0 somehow,

Unpack the 5.8.9 tarball again (if necessary) and "make uninstall". They are both there and will not have corrupted one another.