Say I have an opam project that has been sucessfuly installed (either with make, opam or dune). How do I then go ahead to create the proj.opam file automatically so I can easily install it in the future? Is there anything I need to manually do? (e.g. I assume I have to write the build and install myelf…?)
e.g.
In python we can do pip freeze > requirements.txt if the project is already installed. So perhaps I could:
- install the coq proj with
make
- proceed to do the
opam version of pip freeze > requirements.txt.
Is this possible? Ideally fully automatically.
Looking at the doc for pip freeze, I think you are looking for opam lock. opam lock ./proj.opam will generate (or update) a proj.opam.locked file with dependencies versions constraints set to be equal to the installed ones.
So there’s multiple options. For specifying the dependencies, it is useful to use dune’s opam generation feature. Then Dune generates you a proper OPAM file. This opam file can then be used with opam lock or opam-monorepo lock to get a reproducible set of dependencies.
what is the dune command that generates my opam file? Thanks!
It is generated automatically when you dune build if you set up the opam integration.