Tests requiring root

[Andreas Enge]

I am trying to package lvm2 as a prerequisite for cryptsetup. Most tests 
fail with:

## teardown.../dev/mapper/control: open failed: Permission denied
Failure to communicate with kernel device-mapper driver.
Command failed

and

mknod: '/tmp/nix-build-
lvm-2.02.98.drv-0/LVM2.2.02.98/test/LVMTEST9148.yiDcLm67OP/dev/testnull': 
Operation not permitted
mknod failed

I suspect one needs to be root to run the tests instead of a build user. Do 
you see a way of carrying out the tests?

Another question: Should we use the name "lvm" or "lvm2"? I am not a fan of 
version numbers being used inside the name of a package, but the official 
name appears to be "lvm2" (used in a non-consistent way; the mailing list 
is called "linux-lvm").

Andreas