The fix is two-fold:
- Adjust the path for the sed call in devel/libgit2 so that we leave out openssl from libgit2.pc's Requires.private line, otherwise libgit2-glib will look for openssl.pc, which does not exist when OpenSSL from base is used.
- Reset libgit2-glib back to 0.26, and import a patch both Arch Linux and openSUSE have been carrying to fix the build with libgit2 0.27.