I'm trying to build a Haskell project[1] which appears to be dependent on an function in a old version of base (GHC.Handle.fillReadBuffer). I've downgraded to Haskell platform 2010.2.0.0 which comes with GHC 6.12.3 (installed by homebrew on MacOS X 10.6.8), and ghc-pkg appears to indicate the backwards compatible library for base is available: $ ghc-pkg list base /Users/ghc6/homebrew/Cellar/ghc/6.12.3/lib/ghc/package.conf.d base-3.0.3.2 base-4.2.0.2 /Users/ghc6/.ghc/i386-darwin-6.12.3/package.conf.d However, when I try to cabal build the package, I get the following error: $ cabal -v build Creating dist/build (and its parents) Creating dist/build/autogen (and its parents) Preprocessing executables for TorDNSEL-0.1.1... Building TorDNSEL-0.1.1... Building executable tordnsel... Creating dist/build/tordnsel (and its parents) Creating dist/build/tordnsel/tordnsel-tmp (and its parents) /Users/ghc6/homebrew/bin/ghc --make -o dist/build/tordnsel/tordnsel -hide-all-packages -fbuilding-cabal-package -package-conf dist/package.conf.inplace -i -idist/build/tordnsel/tordnsel-tmp -isrc -idist/build/autogen -Idist/build/autogen -Idist/build/tordnsel/tordnsel-tmp -optP-include -optPdist/build/autogen/cabal_macros.h -odir dist/build/tordnsel/tordnsel-tmp -hidir dist/build/tordnsel/tordnsel-tmp -stubdir dist/build/tordnsel/tordnsel-tmp -package-id HUnit-1.2.2.1-6237339c6ad5673d3cd8f82c4c7f6343 -package-id array-0.3.0.1-438000c197b51c147f229b54edbf632e -package-id base-3.0.3.2-260693a92016991a03206b5a55f6a411 -package-id binary-0.5.1.0-b72d4a82a5aecd9243ff0f50456b3d47 -package-id bytestring-0.9.1.7-64b858f95ff0dacc8acf396bb53cf4b9 -package-id containers-0.3.0.0-ee442470d8dcc9e45f31677c400c5379 -package-id directory-1.0.1.1-fa3418f21f42269537be694d5922dd6d -package-id mtl-1.1.0.2-336254fecf8a77054f76cb33671a5177 -package-id network-2.2.1.7-2eb3746f71ba30c3e4940b75df5ea8b8 -package-id stm-2.1.2.1-95639ea16e2e2cbf4accbabda98a1809 -package-id time-1.1.4-d9f7b7932dc3a4863006ed6b1d525856 -package-id unix-2.4.0.2-94ca14c8a73570f9d75aca642b4de0c6 -O -O2 -Wall -DVERSION="0.1.1-dev" src/tordnsel.hs -lcrypto [ 4 of 39] Compiling TorDNSEL.Util ( dist/build/tordnsel/tordnsel-tmp/TorDNSEL/Util.hs, dist/build/tordnsel/tordnsel-tmp/TorDNSEL/Util.o ) src/TorDNSEL/Util.hsc:143:23: Module `GHC.Handle' does not export `fillReadBuffer' src/TorDNSEL/Util.hsc:143:39: Module `GHC.Handle' does not export `readCharFromBuffer' src/TorDNSEL/Util.hsc:145:26: Module `GHC.IOBase' does not export `Buffer(..)' The flags to ghc indicate that base-3.0.3.2 is being requested, and the documentation for base-3.0.3.2 indicates that GHC.Handle.fillReadBuffer exists[2]. Can anyone explain why I am getting this error message? Could it be because Util is a .hsc rather than .hs file? In tordnsel.cabal I've made two changes: set Build-Depends to include "base>=2.0 && < 4" to tell ghc that I really want base-3 and removed -Werror from GHC-Options (to ignore the deprecation warnings). Otherwise it is as provided in this distribution[3]. Building manually has the same result (though oddly I get a deprecation warning from building the .hs files but not the .hsc file, which led to my suspicion about hsc being an issue. $ hsc2hs TorDNSEL/Util.hsc $ ghc -package-id base-3.0.3.2-260693a92016991a03206b5a55f6a411 --make TorDNSEL/Util.hs [1 of 3] Compiling TorDNSEL.DeepSeq ( TorDNSEL/DeepSeq.hs, TorDNSEL/DeepSeq.o ) TorDNSEL/DeepSeq.hs:1:0: Warning: Module `Prelude' is deprecated: You are using the old package `base' version 3.x. Future GHC versions will not support base version 3.x. You should update your code to use the new base version 4.x. TorDNSEL/Util.hs:1:11: Warning: -#include and INCLUDE pragmas are deprecated: They no longer have any effect [2 of 3] Compiling TorDNSEL.Compat.Exception ( TorDNSEL/Compat/Exception.hs, TorDNSEL/Compat/Exception.o ) TorDNSEL/Compat/Exception.hs:1:0: Warning: Module `Prelude' is deprecated: You are using the old package `base' version 3.x. Future GHC versions will not support base version 3.x. You should update your code to use the new base version 4.x. [3 of 3] Compiling TorDNSEL.Util ( TorDNSEL/Util.hs, TorDNSEL/Util.o ) TorDNSEL/Util.hsc:143:23: Module `GHC.Handle' does not export `fillReadBuffer' TorDNSEL/Util.hsc:143:39: Module `GHC.Handle' does not export `readCharFromBuffer' TorDNSEL/Util.hsc:145:26: Module `GHC.IOBase' does not export `Buffer(..)' Thanks in advance, Steven. [1] https://gitweb.torproject.org/tordnsel.git [2] http://hackage.haskell.org/packages/archive/base/3.0.3.2/doc/html/GHC-Handle... [3] https://gitweb.torproject.org/tordnsel.git/blob/HEAD:/tordnsel.cabal