On 2014-05-01, at 23:46, Edward Kmett wrote:

With the old custom linker we weren't able to get our custom MPFR linked in properly on all platforms for use in ghci.

On Macs we ran into some rather interesting problems. We could get it to work for actual executables, but ghci would segfault with stuff resolved to clearly wrong addresses. If I recall correctly it may have been some kind of MachO symbol type that wasn't being resolved properly by the custom GHC linker, perhaps? We chased after it off and on for a long time to no avail.

Did these segfaults look like the following GHCi 7.6.3 crash? https://ghc.haskell.org/trac/ghc/ticket/9278 It looks like Jason ran into something similar last year: https://gist.github.com/dagit/5986541 Unfortunately, while the new linker in GHCi 7.8.2 doesn’t suffer from this problem, there appears to be another issue: https://ghc.haskell.org/trac/ghc/ticket/9277 Any clues? Thanks, -- Miëtek