Fix udev rules directory

[jorti]

The udev rules always must be installed in /lib/udev/rules.d even when it is
a 64 bits OS

[Benjamin-Dobell]

I did actually wonder about this myself. You wouldn't happen to be able to provide a reference to documentation on the matter?

Honestly, I have no idea why the udev developers decided to use /usr/lib instead of /usr/share.

Anyway, I'll quickly test this out on a couple of my VMs to verify, but I imagine you're quite correct, in which case I'll merge this in.

[jorti]

It's placed in /lib because it's architecture independent. (Or in /usr/lib in distributions like Fedora or Arch, see: http://www.freedesktop.org/wiki/Software/systemd/TheCaseForTheUsrMerge/ )

[Benjamin-Dobell]

Your link does not refer to the usage of /usr/lib (or /lib) vs. /usr/lib64 (/lib64).

Whilst you're probably right that the udev rules need to be in /usr/lib, this seems more like an error in implementation by the udev developers. /usr/lib is by no means for architecture independent files, it's for 32-bit binaries, which is why there is a separate /usr/lib64 for 64-bit binaries. /usr/share is the correct directory for architecture independent files (text-based file formats specifically): http://www.pathname.com/fhs/2.2/fhs-4.11.html

[floppym]

See my commit above for a more robust solution which uses pkg-config.

As for documentation, please see the udev_rules_new function in the udev source code. The rules are loaded from /etc/udev/rules.d, /run/udev/rules.d, and UDEVLIBEXECDIR/rules.d. The latter path is exposed to consumers via the udev.pc file.

http://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-rules.c#n1578