When building 1.8.4 RPMs on CentOS 7 it fails when looking for libks, signalwire-client-c.

I was looking for the source to build RPMs but couldn't find the source debs either.

Are these binary only packages?

root@6f121bb43cbd:/# apt-cache showsrc libks
W: Unable to locate package libks
N: No packages found

root@6f121bb43cbd:/# apt-cache showsrc signalwire-client-c
W: Unable to locate package signalwire-client-c
N: No packages found