Linking error compiling Cabal with custom snapshot #1356
Description
This issue is similar to #1110 but that one is fixed for me, and this isn't. If I compile Cabal-1.22.4.0 on a custom snapshot based on ghc-7.8 which includes a newer unix than comes with that ghc (2.7.1.0 instead of 2.7.0.1), there is an error linking the setup executable for Cabal:
-- While building package Cabal-1.22.4.0 using:
/usr/local/bin/ghc --make -odir /tmp/stack31011/Cabal-1.22.4.0/.stack-work/dist/x86_64-linux/Cabal-1.18.1.3/setup/ -hidir /tmp/stack31011/Cabal-1.22.4.0/.stack-work/dist/x86_64-linux/Cabal-1.18.1.3/setup/ -i -i. -package=Cabal-1.18.1.3 -clear-package-db -global-package-db -package-db=/home/erik/.stack/snapshots/x86_64-linux/custom-silk-2015-09/7.8.3/pkgdb/ /tmp/stack31011/Cabal-1.22.4.0/Setup.hs -o /tmp/stack31011/Cabal-1.22.4.0/.stack-work/dist/x86_64-linux/Cabal-1.18.1.3/setup/setup
...
<snip compiling modules>
....
Linking /tmp/stack31011/Cabal-1.22.4.0/.stack-work/dist/x86_64-linux/Cabal-1.18.1.3/setup/setup ...
/usr/local/lib/ghc-7.8.3/unix-2.7.0.1/libHSunix-2.7.0.1.a(execvpe.o): In function `pPrPr_disableITimers':
execvpe.c:(.text+0x340): multiple definition of `pPrPr_disableITimers'
/home/erik/.stack/snapshots/x86_64-linux/custom-silk-2015-09/7.8.3/lib/x86_64-linux-ghc-7.8.3/unix-2.7.1.0/libHSunix-2.7.1.0.a(ghcrts.o):(.text+0x0): first defined here
The weird thing is that this only happens on linux (Ubuntu 14.04.1 LTS), not on Mac. I've uploaded a reproduction here. Further information: stack Version 0.1.6.0, Git revision e22271f5ce9afa2cb5be3bad9cafa392c623f85c (2313 commits) x86_64, ghc 7.8.3.
/usr/local/lib/ghc-7.8.3/package.conf.d
Cabal-1.18.1.3
HTTP-4000.2.12
HTTP-4000.2.16.1
QuickCheck-2.7.6
array-0.5.0.0
base-4.7.0.1
bin-package-db-0.0.0.0
binary-0.7.1.0
bytestring-0.10.4.0
containers-0.5.5.1
cpphs-1.18.5
deepseq-1.3.0.2
directory-1.2.1.0
filepath-1.3.0.2
ghc-7.8.3
ghc-prim-0.3.1.0
haskeline-0.7.1.2
haskell2010-1.1.2.0
haskell98-2.0.0.3
hoopl-3.10.0.1
hpc-0.6.0.1
integer-gmp-0.5.1.0
mtl-2.1.3.1
network-2.4.2.3
old-locale-1.0.0.6
old-time-1.1.0.2
parsec-3.1.5
polyparse-1.9
pretty-1.1.1.1
primitive-0.5.3.0
process-1.2.0.0
random-1.0.1.1
rts-1.0
setenv-0.1.1.1
stm-2.4.3
tar-0.4.0.1
template-haskell-2.9.0.0
terminfo-0.4.0.0
text-1.1.0.1
tf-random-0.5
time-1.4.2
transformers-0.3.0.0
unix-2.7.0.1
xhtml-3000.2.1
zlib-0.5.4.1