[58 of 58] Compiling Main             ( /tmp/Cabal-1.8.0.69684/Cabal-1.8.0.6/Setup.hs, /tmp/Cabal-1.8.0.69684/Cabal-1.8.0.6/dist/setup/Main.o )
Linking /tmp/Cabal-1.8.0.69684/Cabal-1.8.0.6/dist/setup/setup ...
/usr/bin/ld: /home/simon/.cabal/lib/unix-2.4.0.2/ghc-6.12.1/libHSunix-2.4.0.2.a(Semaphore.o):(.text+0x40f): error: undefined reference to 'sem_trywait'
/usr/bin/ld: /home/simon/.cabal/lib/unix-2.4.0.2/ghc-6.12.1/libHSunix-2.4.0.2.a(Semaphore.o):(.text+0x52b): error: undefined reference to 'sem_post'
/usr/bin/ld: /home/simon/.cabal/lib/unix-2.4.0.2/ghc-6.12.1/libHSunix-2.4.0.2.a(Semaphore.o):(.text+0x87b): error: undefined reference to 'sem_wait'
/usr/bin/ld: /home/simon/.cabal/lib/unix-2.4.0.2/ghc-6.12.1/libHSunix-2.4.0.2.a(Semaphore.o):(.text+0xbe3): error: undefined reference to 'sem_close'
/usr/bin/ld: /home/simon/.cabal/lib/unix-2.4.0.2/ghc-6.12.1/libHSunix-2.4.0.2.a(Semaphore.o):(.text+0xdc6): error: undefined reference to 'sem_open'
/usr/bin/ld: /home/simon/.cabal/lib/unix-2.4.0.2/ghc-6.12.1/libHSunix-2.4.0.2.a(Semaphore.o):(.text+0x1107): error: undefined reference to 'sem_unlink'
/usr/bin/ld: /home/simon/.cabal/lib/unix-2.4.0.2/ghc-6.12.1/libHSunix-2.4.0.2.a(Semaphore.o):(.text+0x1363): error: undefined reference to 'sem_getvalue'
collect2: ld returned 1 exit status
cabal: Error: some packages failed to install:
Cabal-1.8.0.6 failed during the configure step. The exception was:
ExitFailure 1