Description of problem:

The devmapper.pc as shipped with device-mapper-devel-1.02.105-1.fc24 is broken.

It tries to reference another *.pc file (librt.pc), which does not exist and causes calls to /usr/bin/pkg-config to fail.

Version-Release number of selected component (if applicable):
device-mapper-devel-1.02.105-1.fc24

How reproducible:
Always

Steps to Reproduce:
1. mock -r fedora-rawhide-x86_64 --init
2. mock -r fedora-rawhide-x86_64 --install \
  'pkgconfig(devmapper)' 'pkgconfig(libselinux)' 'pkgconfig(libudev)'
3. mock -r fedora-rawhide-x86_64 --shell
4. Run pkg-config inside of the chroot:
# pkg-config --cflags devmapper
Package librt was not found in the pkg-config search path.
Perhaps you should add the directory containing `librt.pc'
to the PKG_CONFIG_PATH environment variable
Package 'librt', required by 'devmapper', not found


Actual results:
cf. above

Expected results:
function.

Additional info:

- The problem here is the reference to librt in /usr/*/pkg-config/devmapper.pc:
...
Libs: -L${libdir} -ldevmapper
Requires.private: libselinux libudev librt

pkg-config expects to find a librt.pc.

This file does not exist, so pkg config errors out.

- This bug already is causing FTBFSs