[Fedora-packaging] problem with scratch build or mock

[philippe makowski <makowski fedora gmail com>]

Hi,
I made the src.rpm under F11
then koji build --scratch dist-5E-epel
/home/philippe/rpmbuild/SRPMS/firebird-2.1.3.18156.0-0.fc11.src.rpm

can someone explain me why I get this :
DEBUG util.py:256:  error: unpacking of archive failed on file
/builddir/build/SOURCES/Firebird-2.1.3.18156-0.tar.bz2;4a3bf995: cpio:
MD5 sum mismatch

and even using mock -r epel-5-i386 rebuild
./SRPMS/firebird-2.1.3.18156.0-0.fc11.src.rpm
on my box I get into the same trouble