Hi All, I have been trying to get a simple-integer build for GHC without success. It always ends with the build going through fine, but when I try to run ghci I get: GHCi, version 6.12.3: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. ghc: /usr/local/ghc/6.12.3-is/lib/ghc-6.12.3/integer-simple-0.1.0.0/HSinteger-sim ple-0.1.0.0.o: unknown symbol `base_ControlziExceptionziBase_patError_info' Loading package integer-simple ... linking ... ghc: unable to load package `integer-simple' My MO is to . get binary GHC package, install it and put it on the path; . unpack the source distribution and set up build.mk, usually with quicktest, always with INTEGER_LIBRARY = integer-simple; . configure, build and install; . switch the path over from the binary to the new build and run ghci. I have tried this many combinations of build and source trees from ghc-6.12.1 up to 7.0.4 on CentOS/RHEL 5 & 6 with the same result. The above output was taken from a 6.12.3 source tree built with 6.12.2 binaries. Further: . I use 6.12.3 binaries heavily on CentOS 5 with no issue. . On the couple of occasions I have tried a vanilla build (no build.mk), the build breaks down with GMP link errors. Configuring with --with-gmp-includes=/usr/local/include and --with-gmp-libs=/usr/local/lib didn't help. (I did not persist for obvious reasons.) . At least Mik Konecny appears to got this to work for 6.12.3 http://code.google.com/p/hmpfr/wiki/GHCWithoutGMP . 'Tis all very odd! Anybody any idea what I am doing wrong? Chris