#705: Non-deterministic behaviour when overlapping packages are installed ---------------------------------+------------------------------------------ Reporter: guest | Owner: Type: defect | Status: new Priority: normal | Milestone: Component: cabal-install tool | Version: 1.8.0.2 Severity: normal | Keywords: Difficulty: unknown | Ghcversion: Platform: | ---------------------------------+------------------------------------------ See [http://stackoverflow.com/questions/3119782/mysterious-cabal-install- problems]. This user took a standard Haskell Platform install, installed a new version of the time package, and then installed random. The random package was rebuilt and installed against the new time package. However, re-running `cabal install random` installs random again; it doesn't reach a fixed point. The problem (I presume) is that when cabal-install merges the package databases it chooses which `random-1.0.0.2` to use non-deterministically. In fact it seems to depend on the exact package Ids, because I get different results with GHC 6.12.2 where the package Ids of the two `random-1.0.0.2` packages are ordered differently. I realise there are larger issues about how to do resolution here, but I think at least we should make cabal-install deterministic, and preferably idempotent. -- Ticket URL: http://hackage.haskell.org/trac/hackage/ticket/705 Hackage http://haskell.org/cabal/ Hackage: Cabal and related projects