I'm spending way too much time backporting 1.6.17 work to RHEL 4, to publish for Repoforge. So far so good, I'm working from Mike Bauer work at plos.org, and tying it to my old Repoforge work for 1.6.x, and that's based on Fedora 16 source RPM's on the last go-round. No big problem so far, it's just a lot of testing changes one at a time.
But there are some side packages that just won't work for RHEL 4. In particular, the "--with-kwallet" option isn't workable with such an old KDE, and the "--with-gnome-keyring" won't build with such an old DBus. (I've got workarounds for --with-kwallet for RHEL 6 compilation, but --with-kwallet doesn't work for RHEL 5, either.) I can disable them from package compilation for RHEL 4, but is there anyone familiar enough with those tools to try backporting them? I realize RHEL 4 is on extended support only, but sometimes migrating people off of old systems really benefits from access to supported source control tools.