Cutsea, have you been able to reproduce this after cleaning your source
#11532: ghc: panic! occured -------------------------------------+------------------------------------- Reporter: cutsea | Owner: Type: bug | Status: infoneeded Priority: high | Milestone: 8.2.1 Component: Compiler | Version: 7.10.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by cutsea): Thanks for your replys. tree? I can reproduce this by following: {{{ $ mkdir sandbox $ cd sandbox $ cabal sandbox init $ cabal install metadata }}} By the way, my environment after occuring panic is: {{{ $ uname -a Linux kona 4.3.0-1-amd64 #1 SMP Debian 4.3.3-7 (2016-01-19) x86_64 GNU/Linux $ cabal sandbox hc-pkg list /usr/lib/ghc/package.conf.d Cabal-1.22.5.0 array-0.5.1.0 base-4.8.2.0 bin-package-db-0.0.0.0 binary-0.7.5.0 bytestring-0.10.6.0 containers-0.5.6.2 deepseq-1.4.1.1 directory-1.2.2.0 filepath-1.4.0.0 ghc-7.10.3 ghc-prim-0.4.0.0 haskeline-0.7.2.1 hoopl-3.10.0.2 hpc-0.6.0.2 integer-gmp-1.0.0.0 pretty-1.1.2.0 process-1.2.3.0 rts-1.0 template-haskell-2.10.0.0 terminfo-0.4.0.1 time-1.5.0.1 transformers-0.4.2.0 unix-2.7.1.0 xhtml-3000.2.1 /home/cutsea110/devel/haskell/sandbox/.cabal-sandbox/x86_64-linux- ghc-7.10.3-packages.conf.d text-1.2.2.0 }}} And my ghc is installed by using apt-get(debian package). -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11532#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler