Oh, I know it's available, I'm just saying that it isn't installed by default because almost nothing [requires it](https://www.archlinux.org/packages/community/any/lsb-release/).

Anyway, how about checking a handful of well-known names/locations first (like /usr/lib/liblua5.1.so) and only fall back to distro detection if that fails?

Finally, if it's only Debian-based distros that have different so names, you could check for these and put everything else in the 'else' clause.

P.S. Does Eluant need 5.1.5 or 5.1.x will do?