Hello, I triggered a confusing behaviour from the opam importer trying to import package iter 1.2.1 today on a Guix System install.
The package iter is missing a "synopsis" field as can be seen on https://opam.ocaml.org/packages/iter/ , which when I tried guix import opam iter yielded the following backtrace: Backtrace: 8 (primitive-load "/home/alice/.config/guix/current/bin/g…") In guix/ui.scm: 2185:7 7 (run-guix . _) 2148:10 6 (run-guix-command _ . _) In guix/scripts/import.scm: 120:11 5 (guix-import . _) In guix/scripts/import/opam.scm: 104:23 4 (guix-import-opam . _) In guix/utils.scm: 752:8 3 (call-with-temporary-output-file _) In guix/import/opam.scm: 337:34 2 (_ _ _) In srfi/srfi-1.scm: 460:18 1 (fold #<procedure 7f3baca56fe0 at guix/import/opam.scm…> …) In guix/import/opam.scm: 193:15 0 (_ _ _) guix/import/opam.scm:193:15: Throw to key `match-error' with args `("match" "no matching pattern" string-pat)'. the final error is raised l.193 of guix/import/opam.scm because metadata-ref supports various types for a metadata field, but not the lack of it. As discussed with Maxime Devos on the IRC channel, it would be helpful to either allow the import of a package with a missing field (possibly filling it in the output scheme code for the imported package with some bad value requiring the user to fill it and causing any build to crash until replaced properly) or at least to handle that missing field with a more explicit error message than the above backtrace (something like "Can't import that package because it's missing such or such field"). Thanks, Alice BRENON
