opam admin add-constraint allow to specify a list of excluded packages

[dbuenzli]

Currently this affects all --depend-on packages but you may want to specify exceptions. Alternatively you may want to specify only a few that should be affected.

[dbuenzli]

opam admin add-constraint is truly excellent but sadly falls short because of this issue.

That being said I don't think you want to specify a list of excluded packages, you want to specify a list of affected packages, namely those whose build you witnessed failing.

A simple way would be to turn the synopsis into:

opam admin add-constraint CONSTRAINT [PKG[.VERSION]...]

[dbuenzli]

Another useful thing would be to output on stdout the affected files (possibly behind a cli switch).

[dbuenzli]

A simple way would be to turn the synopsis into:

opam admin add-constraint CONSTRAINT [PKG[.VERSION]...]

And to be clear this should also add the constraint on the given packages even if the constraint is not currently in the specified package's deps.

[kit-ty-kate]

I don’t personally have time to dedicate to this at the moment but this seems to be "workaroundable" with a simple bash script such as:

add-constraint-except.sh:

#!/bin/bash

opam admin add-constraint "$1"
sed_args=() ; for pkg in $2; do sed_args=("${sed_args[@]}" -e "/^packages\\/$pkg/{p;n;}"); done
git restore -- $(git status --short | grep "^ M " | sed "s/^ M //" | sed -n "${sed_args[@]}")

[dbuenzli]

Yes it's always workaroundable with a dose of shell scripting :-(

The add constraint everywhere and then commit only those files you want to change works. But it's a tad annoying.

For reference in this case combining with @dra27's sed runes to get the failure from CI. I get to something like:

opam admin add-constraint 'cmdliner<1.1.0'
curl -Ls https://opam.ci.ocaml.org/github/ocaml/opam-repository/commit/9e1c4741f678920dce29d3280af125f48430e81d \
| sed -e 's/>/\n/g' \
| sed -nE 's/^([^ ]*) \(failed: (This|Unbound|The).*/\1/p' \
| sort \
| uniq \
| sed 's/\(\([^\.]*\).*\)/packages\/\2\/\1\/opam/g' \
| git add --pathspec-from-file=-
git checkout packages
git commit -m 'Constrain failures on cmdliner 1.1.0'

[kit-ty-kate]

just in case you want to have a shot at doing it, it seem relatively easy:

opam/src/client/opamAdminCommand.ml

Line 1036 in 2b75470

OpamPackage.Map.iter (fun nv prefix ->

This would be just a matter of a couple of ifs and a new argument around here I believe

[dbuenzli]

After five years, I'm still very very interested in having a good workflow for fixing massive opam-repository failures (see e.g. ocaml/opam-repository#22598) and this is part of it.

Could this please be put on a release target ?

[dbuenzli]

Thank you @rjbou ! I missed the resolution. Look forward to integrate that in my tooling.