Building Mozilla applications (Firefox, Thunderbird, SeaMonkey, etc.) on modern Linux distributions is generally relatively trouble-free, although each new distribution tends to introduce a few new issues that need to be fixed in the source. Fedora Core 5 introduces two such issues:
Compilation errors relating to JB_BP
Depending on the version of your source and configuration options, you may see compilation errors related to the removal of JB_BP, which was a constant used in code that took stack traces for debugging purposes by getting the frame address by calling setjmp. Patches to fix these problems are in bug 323853.
The patch that affects the default build options has been checked in to the trunk, the MOZILLA_1_8_BRANCH, and the MOZILLA_1_8_0_BRANCH. However, if you are using other debugging tools, particularly on older branches, or building from older branches or release tags, you may need to apply some of these patches yourself.
SELinux execmod denials
For those with SELinux in enforcing mode, you are likely to run into problems both with the shlibsign during the build process and with the running the final build related to SELinux denying execmod permission due at least primarily (if not completely) to a compiler bug.
The workaround is to use a command like (using bash syntax):
chcon -t texrel_shlib_t $(find . -name "*.so")