#4012: Compilation results are not deterministic -------------------------------------+------------------------------------- Reporter: kili | Owner: niteria Type: bug | Status: new Priority: high | Milestone: 8.2.1 Component: Compiler | Version: 6.12.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Other | Test Case: Blocked By: 11362 | Blocking: 12262 Related Tickets: #10424 | Differential Rev(s): Phab:D910, | Phab:D1073, Phab:D1133, Phab:D1192, | Phab:D1268, Phab:D1360, Phab:D1373, Wiki Page: | Phab:D1396, Phab:D1457, Phab:D1468, DeterministicBuilds | Phab:D1487, Phab:D1504, Phab:D1508 -------------------------------------+------------------------------------- Comment (by Bartosz Nitka <niteria@…>): In [changeset:"9858552d607f643db0385be2133a04dd4b5ff753/ghc" 9858552d/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="9858552d607f643db0385be2133a04dd4b5ff753" Use deterministic maps for FamInstEnv We turn FamInstEnvs into lists in some places which don't directly affect the ABI. That happens in family consistency checks and when producing output for `:info`. Unfortunately that nondeterminism is nonlocal and it's hard to tell locally what it affects. Furthermore the envs should be relatively small, so it should be free to use deterministic maps here. Testing with nofib and ./validate detected no difference between UniqFM and UniqDFM. GHC Trac: #4012 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4012#comment:228> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler