I'd like to see a simpler process for comparing challenge results
While the manual documents how to compare a failing challenge result
$ wget -q -O - https://ci.guix.info/nar/…-git-2.5.0\
| guix archive -x /tmp/git
$ diff -ur --no-dereference /gnu/store/…-git.2.5.0 /tmp/git
To check "git", you need to run "guix challenge git" and if the results
are inconclusive, manually cut-and-paste the correct URL(s) from the
challenge output and manually download it and unpack with guix archive,
and then run a comparison utility...
What about an argument to "guix challenge" that handles the downloading
and unpacking to a temporary directory, and possibly another that also
runs a comparison tool against the results. Maybe something like:
$ guix challenge --download-differences
Downloads and unpacks the substitutes, and outputs the resulting
$ guix challenge --download-differences --compare-with="diffoscope ..."
This would do the above, plus run diffoscope on the directories
... though I think diffoscope can only compare between two things at a
time... so that might get difficult if many substitutes return results.