This page explains how you can contribute to reproducible builds in GNU Guix.

Finding reproducibility issues

You can monitor reproducibility issues by running guix challenge. To further investigate, you can specify one or more packages on the command line, and ask it to invoke Diffoscope upon failure:

guix challenge git \
  --diff=diffoscope \

Another option is to rebuild packages locally. For example, assuming you already installed Git on your machine, you can force a rebuild with --check:

guix build git --check --no-grafts --keep-failed

If the new build result differs from the one that was already in store, the failed build is kept as /gnu/store/…-git-1.2.3-check, allowing you to compare it with the original one (without the -check suffix).

Reporting issues

Please report issues by sending email to Each message opens a new issues visible in the bug tracker.

When investigating, be sure to check Debian’s reproducibility issue inventory for known problems and solutions.

You can also discuss these issues with other developers on the Guix development mailing list and on the IRC channel.