Also note that the upstream test-suite run in the CI does actually
provide the expected output. Obviously you can't use the ENV variable to
automatically overwrite your files, but you certainly can copy out the
diffs from the CI. Just commit empty files in place for the output files
and the CI will complain that they differ including the full difference.
We tried doing this and we failed on CI, but the pipeline jobs didn't output a diff, and instead simply errored out with the message "Full log written to /builds/bschoney/libvirt/build/meson-private/dist-build/meson-logs/testlog.txt". How can we actually view the diff against our blank file? We're trying to find the output for the qemuxml2argvdata args file for our new test but it's not being printed anywhere.