Reproducing Copr builds locally

In a nutshell, the build-logic in Copr is implemented as set of utilities that form a thin wrapper around Mock. So Mock needs to be configured.

Then, it should be relatively trivial to reproduce the build on your local machine. The howto is dumped into every single builder-live.log.gz file like:

You can reproduce this build on your computer by running:

  sudo dnf install copr-rpmbuild
  /usr/bin/copr-rpmbuild --verbose --drop-resultdir --task-url --chroot fedora-rawhide-x86_64

Feel free to start with that workflow. The Copr instance administrators should pay attention to make the reproducibility as simple as that. But some situations may require additional configurations though; notable examples:

  1. You might need your own Red Hat subscription-manager credentials, if building against RHEL based chroots.

  2. Some configuration fixes in mock-core-configs package might be required (or additional configuration files added); Copr administrators might do temporary hacks around broken distribution repositories, broken build methods, etc. That’s why the copr-rpmbuild utility dumps the configs.tar.gz file into every single result directory. If needed, you can download the tarball and extract the appropriate piece of configuration into one of the Mock configuration directories.

  3. For non-public DistGit instances, configured typically in non-public Copr instances, may need a config file in /etc/copr-distgit-client/. Ask your Copr admins to provide the configuration file for you.

  4. Uploaded spec files and SRPMs are very quickly removed from Copr Frontend, right after the sources are imported into DistGit. Such “source builds” (not really builds in this sense) that just download stuff from Copr Frontend will fail for you locally claiming that the source doesn’t exist, error 404. This typically isn’t a problem; you don’t want to reproduce “source build”, but the particular binary RPM build.