bzip2-1.0.8 does not include support for pkg-config, but all major linux distributions included it, by providing the script directly to the package. See for example the sources of that package for arch linux:
https://gitlab.archlinux.org/archlinux/packaging/packages/bzip2 I did a similar thing, by adding a bzip2.pc.in, which will be used by the cygport script for generating the bzip2.pc file. While I was on the topic, I also improved a bit the script, by adding the information about the license. I hope that the maintainer of the BZip2 package for CYGWIN will find it useful. Sincerely, Carlo Bramini.
bzip2.cygport
Description: Binary data
bzip2.pc.in
Description: Binary data
