When the ABI doesn't match the package version...

While investigating https://github.com/conda-forge/zeromq-feedstock/issues/36 I learned that the libsodium package version (e.g. 1.0.16) doesn't reflect the ABI version (24 in 1.-.15-16, 23 in 13, 18 in 1.0.8, etc.). In the meantime, I'm pinning run_exports with max_pin=x.x.x since I can't *know* the next patch version won't bump the ABI version, even though it probably won't.

So the question has been raised: how to pin *abi compatibility* in run_exports, when the version number of the package isn't enough.

A few options have been proposed on gitter:

- add a libsodium25 output, so the ABI version is in the package name (like debian)
- add a libsodium_abi output with the ABI version
- prepend the ABI major version in the library package version (libsodium-24.1.0.16)