New review comment by dkosovic on void-packages repository

https://github.com/void-linux/void-packages/pull/23646#discussion_r458586552

Comment:
I'll try and come up with something.

Unfortunately the upstream ppp package doesn't use pkgconfig yet.  For the PPP based NetworkManager VPNs, Debian uses `dh_ppp --plugin-dir`, OpenSUSE has `%requires_eq ppp`, Fedora does a similar `sed` on `/usr/include/pppd/patchlevel.h`.

For the `depends`, I would have liked to have had something like `ppp=${PPP_VERSION}`, to enforce that the package should get rebuilt whenever a new version of the ppp package comes along which uses a pppd plugin dir location based on the ppp version number.