emerge breaks haskell packages due to missing passthru subslot style depends about gentoo-haskell HOT 4 OPEN

It's not dependency hell, but ABI hell.

Try to use haskell-updater to partially mitigate the breakage.

Haskell's ABI is not stable at all. Every signature/optimization, inline
change breaks ABI.
Thus you need to rebuld all the reverse dependencies
of upgraded package.

Yes, package managers are expected to solve this kind of issues,
and EAPI=5 ebuilds made a step in that direction (we use those funky subslot depends).
However, currently subslots only allow rebuilding one step in revdep chain.

We need to rebuild full graph. There is plans for EAPI=6 to support it, but not now.

from gentoo-haskell.

Filled as portage feature request: http://bugs.gentoo.org/449094

from gentoo-haskell.

So, as a temporary workaround to this is it feasible to build a tool that would:

1. Calculate every affected reverse dependency in a given commit
2. Bump the version in each affected reverse-dependency to r1, r2, etc...

I realize this is a bit "hackey", and it is a temporary solution for sure, but it could make haskell life in gentoo just a tad more livable.

from gentoo-haskell.

Sounds plausible

from gentoo-haskell.