Hi, I just got the same thing with attoparsec GIT: Preprocessing benchmark 'benchmarks' for attoparsec-0.10.4.0... Building benchmark benchmarks... creating dist/build/benchmarks creating dist/build/benchmarks/benchmarks-tmp /home/niklas/opt/haskell-7.4/bin/ghc --make -fbuilding-cabal-package -O -odir dist/build/benchmarks/benchmarks-tmp -hidir dist/build/benchmarks/benchmarks-tmp -stubdir dist/build/benchmarks/benchmarks-tmp -i -idist/build/benchmarks/benchmarks-tmp -ibenchmarks -idist/build/autogen -Idist/build/autogen -Idist/build/benchmarks/benchmarks-tmp -optP-include -optPdist/build/autogen/cabal_macros.h -hide-all-packages -package-conf dist/package.conf.inplace -package-id base-4.5.1.0-66f22db3dfcd87541c9c7e50e7095d26 -package-id bytestring-0.9.2.1-503e91bb155301fdb1956cb5c26ce6e9 -package-id criterion-0.6.2.1-5bc7e5a96c8208948366b8e3ea536e68 -package-id deepseq-1.3.0.0-c26e15897417ecd448742528253d68f6 -package-id parsec-3.1.3-771f99c8818551756b6f2ec3e86ab039 -package-id text-0.11.2.3-db61832d0c4660614c4ceff234ed4abb -package-id attoparsec-0.10.4.0-inplace -XHaskell98 benchmarks/Benchmarks.hs -o dist/build/benchmarks/benchmarks <command line>: cannot satisfy -package-id attoparsec-0.10.4.0-inplace: attoparsec-0.10.4.0-inplace is shadowed by package attoparsec-0.10.4.0-c391286d724823eaea3d4278acc0acc0 (use -v for more information) I have no clue what's going on!