I had the following build error recently while building Firefox using Fedora Core 12.
make[6]: Entering directory `/home/HomeDir/src/obj-i686-pc-linux-gnu/toolkit/crashreporter/google-breakpad/src/tools/linux/dump_syms'
c++ -o dump_syms -frtti -fno-exceptions -Wall -Wpointer-arith -Woverloaded-virtual -Wsynth -Wno-ctor-dtor-privacy -Wno-non-virtual-dtor -Wcast-align -Wno-invalid-offsetof -Wno-variadic-macros -Werror=return-type -Wno-long-long -pedantic -fno-strict-aliasing -fshort-wchar -pthread -pipe -DDEBUG -D_DEBUG -DDEBUG_HomeDir -DTRACING -g -O -g -static host_dump_syms.o ../../../../../../../toolkit/crashreporter/google-breakpad/src/common/linux/libhost_breakpad_linux_common_s.a ../../../../../../../toolkit/crashreporter/google-breakpad/src/common/libhost_breakpad_common_s.a ../../../../../../../toolkit/crashreporter/google-breakpad/src/common/dwarf/libhost_breakpad_dwarf_s.a
/usr/bin/ld: cannot find -lm
collect2: ld returned 1 exit status
make[6]: *** [dump_syms] Error 1
make[6]: Leaving directory `/home/HomeDir/src/obj-i686-pc-linux-gnu/toolkit/crashreporter/google-breakpad/src/tools/linux/dump_syms'
make[5]: *** [libs] Error 2
make[5]: Leaving directory `/home/HomeDir/src/obj-i686-pc-linux-gnu/toolkit/crashreporter'
make[4]: *** [crashreporter_libs] Error 2
make[4]: Leaving directory `/home/HomeDir/src/obj-i686-pc-linux-gnu/toolkit'
make[3]: *** [libs_tier_platform] Error 2
make[3]: Leaving directory `/home/HomeDir/src/obj-i686-pc-linux-gnu'
make[2]: *** [tier_platform] Error 2
make[2]: Leaving directory `/home/HomeDir/src/obj-i686-pc-linux-gnu'
make[1]: *** [default] Error 2
make[1]: Leaving directory `/home/HomeDir/src/obj-i686-pc-linux-gnu'
make: *** [build] Error 2
The work around is to disable the building of the Crash Reporter in your .mozconfig.
ac_add_options --disable-crashreporter
According to the searches I did glibc-devel should have provided -lm and libm.so. I had it installed but continued to have this build problem.
