This morning, Anil proposed that having an opam-repository that didn’t have old versions of the packages that require patches to work with OxCaml would be good.
This is a fast-moving area, so this post is likely to be outdated very quickly, but at the time of writing, the development repository is https://github.com/janestreet/opam-repository#with-extensions. This is a fork of opam-repository but with some patched packages designated with +ox.
I have a short shell script which clones both opam-repository and https://github.com/janestreet/opam-repository#with-extensions and searches for all packages with +ox. All versions of these packages are removed from opam-repository and replaced with the single +ox version. The resulting repository is pushed to https://github.com/mtelvers/opam-repository-ox.
To test the repository (and show that eio doesn’t build), I have created a Dockerfile based largely on the base-image-builder format. This Dockerfile uses this modified opam-repository to build an OxCaml switch.
My build script and test Dockerfile are in [https://github.com/mtelvers/opam-repo-merge] (https://github.com/mtelvers/opam-repo-merge). Thanks to David for being the sounding board during the day!