Hi, you could fork the cctbx_project into your personal github account, then check out the forked repository locally. Make the changes to support Fedora and push them back as commits to your forked repository. Then, make a local edit to bootstrap.py to pull from your repository. Something like this (lines 755-757):
# Core CCTBX repositories
# These must all provide anonymous access.
class cctbx_module(SourceModule):
module = 'cctbx_project'
anonymous = ['git',
'git@github.com:cctbx-xfel/cctbx_project.git',
(as seen in this commit)
You can use that edited bootstrap to test your changes.
Does that make sense? When you are done, you can push the changes back using a pull request from your forked repository.