koji build fail but not with mock

[jonathan]

Dear,

I search to know for which reason th build fail through koji:
http://koji.fedoraproject.org/koji/taskinfo?taskID=4131995

I have try to build with mock:
wget
http://bioinfornatics.fedorapeople.org/ldc-2-20.20120605git6ad085a.fc17.src.rpm
mock -r fedora-17-x86_64 rebuild
ldc-2-20.20120605git6ad085a.fc17.src.rpm


the build success

I have send to some friend the src.rpm and same they get a successful
rebuild.

koji seem to use same: gcc cpp llvm gc glibc

if someone can tell to me what is wrong?

thanks

kind regards