Frequently Asked Questions

This section will grow over time, and should gather replies to Frequently Asked Questions.

The patch didn’t apply correctly. What shall I do ?

Most of the time, we didn’t have time to test a patch that we made for a version on other versions of the same package. It’s often the case that they will work without modification.

For a given version of a package, opam-bin selects the patch with the higest version less or equal to the package being installed. Sometimes, it would be better to use the patch for the version just higher. This is a good way to solve your problem.

For that, you will have to use a local version of the relocation-patches directory:

git clone
opam bin config --patches-url file://$(pwd)/relocation-patches
cd relocation-patches/patches/$NAME/
cp $NEXT_VERSION.patch $VERSION.patch

Why not upstream patches to opam-repository ?

Patches in the relocation-patches repository should be upstreamed to opam-repository over time, but the problem is that they should be applied to many versions of the same packages. For example, the ocaml-variants package contains tens of packages for every version of OCaml. So, it would take a lot of work. Instead, opam-bin is able to automatically patch a range of versions using a single patch.