On Wed, Oct 05, 2016 at 03:06:11PM +0000, Clint Adams wrote: > haskell-http-link-header fails to build on the powerpc buildds. It > builds fine in a sid chroot on partch, so I have no idea how to > reproduce this. > > Does anyone have any insight?
The last time this happened (in May I believe) someone pointed at this: https://ghc.haskell.org/trac/ghc/ticket/12070 Sounds plausible. power7 and power8 machines are very picky about proper memory barriers, and a lot of code that "worked" on power6 and older started to fail a lot on power7 and newer. Now since you end up with race conditions, you might get 'lucky" and not fail when you run it. The build failed on a power8 machine, while you tested on a power7 machine. The power8 machine is likely to be even more parallel and more likely to hit any synchronization issues than the power7. So if that is the issue, it appears to be fixed in ghc upstream in version 8, while the build was using 7.10.3. -- Len Sorensen
