Please take a look at the srpm in https://bugzilla.fedora.us/show_bug.cgi?id=1113 . I was able to build it without much trouble, but the thunderbird program hangs and gives no info. Please either take a look at the strace I made or download and compile that srpm yourself. Bare in mind that its missing the source.
download http://members.ii.net/~the_hills/thunderbird-0.5-0.fdr.4.src.rpm download http://ftp.mozilla.org/pub/mozilla.org/thunderbird/releases/0.5/thunderbird-... unzip thunderbird-0.5-source.tar.gz find the thunderbird-0.5-source.tar.bz2 within and copy it to your SOURCE directory, then build the spec. That's what I did anyway. It builds without errors, but does not run. Please see if it runs on your system, and mine is broken, or whether the rpm is problematic.
-Eric Hattemer