Alexander Neundorf authored Nov 12, 2011 and Brad King committed Nov 22, 2011

Typical <package>Config.cmake files for find_package() rely only on the
files generated by install(EXPORT).  They might be wrong, for whatever
reasons, like people manually deleted files, projects were packaged
wrong by distributions, whatever.  To protect against this, add checks
that the file locations we are importing actually exist on disk.

Alex