As you've probably noticed [1], redhat-rpm-config-8.0.35 and later have started using the brp-python-bytecompile script to byte-compile python scripts at the end of %install. What does this mean for your package? If your package specifies a buildroot, after the %install phase completes, rpmbuild will now find .pyc and .pyo files sitting alongside any .py files which were installed under $RPM_BUILD_ROOT. If your package's %files list doesn't mention these files, you'll need to update it to get the package to build successfully without tripping the unpackaged-files-in-buildroot sanity check. The procedure is similar to what we all needed to do when we started compressing man pages by default, tedious but simple: either change every instance of ".py" to ".py*", or add the .pyc and .pyo files to the %files list individually. If your package was explicitly byte-compiling modules in the %install scriptlet, you can now, at your option, stop it from doing so. If your package uses distutils to build an RPM (specifically, if it calls "python setup.py install" with the "--record" option to generate its %files list), then you'll need to add the "-O1" flag to the command to get a correct list. Yes, this makes the packages larger. How much larger is entirely dependent on how much python code the package contains. [2] HTH, Nalin [1] http://www.redhat.com/archives/fedora-devel-list/2005-June/msg01043.html [2] You can filter the "rpm -qlv" output through awk 'BEGIN{size=1;pyosize=0;pycsize=0;pysize=0}/\.py$/{pysize=pysize+$5}/\.pyc$/{pycsize=pycsize+$5}/\.pyo$/{pyosize=pyosize+$5}{size=size+$5}END{printf ".py:%7.2f%%\n",pysize*100/size;printf ".pyc:%6.2f%%\n",pycsize*100/size;printf ".pyo:%6.2f%%\n",pyosize*100/size}' to get a breakdown of how much space python files take up in a package.