@trommler, how are you triggering these errors? Unfortunately, I cannot directly observe these errors. I see them on Open(SUSE) Build Service where a build runs inside a qemu VM on a POWER8. The issue is very rare, 1700 packages build just fine and around 30 to 50 fail. Most of the failures are in `Setup`, which we compile for each
#12469: Memory fence on writes to MutVar/Array missing on ARM -------------------------------------+------------------------------------- Reporter: rrnewton | Owner: Type: bug | Status: patch Priority: normal | Milestone: 8.0.2 Component: Compiler | Version: 8.0.1 Resolution: | Keywords: memory model Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect result | Unknown/Multiple at runtime | Test Case: Blocked By: | Blocking: 12537 Related Tickets: | Differential Rev(s): Phab:D2495 Wiki Page: | Phab:D2525 -------------------------------------+------------------------------------- Comment (by trommler): Replying to [comment:20 erikd]: package, and very few (less than 3) fail with a panic. Rebuilding the package works with high probability. On my PowerMac quad core I see a segfault in `./Setup build -v -j4` which is what is reported in #12537. In that ticket a compiler panic in `mkFastStringWith` is reported but I have not been able to provoke a panic on my machine. Is it worth trying some more runs and hope to observe a panic to rule out that qemu is doing something odd? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12469#comment:21 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler