Why does source compile fail on archlinux at gcc?

edit

I am attempting to compile the most recent sage source code on my Archlinux system. I have all the required packages and tools, and so I would have expected that make would simply do its bit.

But it fails on the compile of gcc. I've included below the last few lines of my gcc log file. What is going wrong here, and how do I fix it?

Makefile:1058: recipe for target 'cp/except.o' failed
make[6]: *** [cp/except.o] Error 1
make[6]: Leaving directory '/opt/sage-7.2/local/var/tmp/sage/build/gcc-4.9.3.p1/gcc-build/gcc'
Makefile:4222: recipe for target 'all-stage1-gcc' failed
make[5]: *** [all-stage1-gcc] Error 2
make[5]: Leaving directory '/opt/sage-7.2/local/var/tmp/sage/build/gcc-4.9.3.p1/gcc-build'
Makefile:18866: recipe for target 'stage1-bubble' failed
make[4]: *** [stage1-bubble] Error 2
make[4]: Leaving directory '/opt/sage-7.2/local/var/tmp/sage/build/gcc-4.9.3.p1/gcc-build'
Makefile:889: recipe for target 'all' failed
make[3]: *** [all] Error 2
make[3]: Leaving directory '/opt/sage-7.2/local/var/tmp/sage/build/gcc-4.9.3.p1/gcc-build'

real    5m46.259s
user    4m57.797s
sys     0m23.407s
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Error installing package gcc-4.9.3.p1
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Please email sage-devel (http://groups.google.com/group/sage-devel)
explaining the problem and including the relevant part of the log file
  /opt/sage-7.2/logs/pkgs/gcc-4.9.3.p1.log
Describe your computer, operating system, etc.
If you want to try to fix the problem yourself, *don't* just cd to
/opt/sage-7.2/local/var/tmp/sage/build/gcc-4.9.3.p1 and type 'make' or whatever is appropriate.
Instead, the following commands setup all environment variables
correctly and load a subshell for you to debug the error:
  (cd '/opt/sage-7.2/local/var/tmp/sage/build/gcc-4.9.3.p1' && '/opt/sage-7.2/sage' --sh)
When you are done debugging, you can type "exit" to leave the subshell.
************************************************************************