cargo/opam have them, I can see the use case, need has not arisen yet
An optional dependency should fork the solver into two solution trees, one with and another without it (in case the dependency is available but makes the solution impossible).
alire-project / alire
Command-line tool from the Alire project and supporting library
285
Contributors get 50% of received funds after fees
How does funding with Polar work?
1
Pay now to fund the work behind this issue.
2
Get updates on progress being made.
3
Maintainer is rewarded once the issue is completed.
FAQ
Backer
You're funding impactful open source efforts
Contributor
You want to contribute to this effort
Maintainer
You want to get funding like this too