I have already opened a GitHub issue about this, but got no response so far: Maintenance · Issue #68 · haskell/parallel · GitHub.
As written in the issue, the parallel
library is pretty much abandoned, with the only commits being dependency bumps for more than a year, despite there being plenty open issues and pull requests. Since noone responded so far, I thought I’d start a discussion here, to get some more attention. I’d be happy to help maintain/develop the library, but someone would have to give me access for that (or actively review issues and PRs).