#10602: ghc panic: Template variable unbound in rewrite rule when compiling with -O2 -------------------------------------+------------------------------------- Reporter: pacak | Owner: bgamari Type: bug | Status: infoneeded Priority: highest | Milestone: 7.10.2 Component: Compiler | Version: 7.10.2-rc2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by pacak): Step by step manual to reproduce {{{ % tar xf ../ghc-7.10.1.20150630-src.tar.xz % cp mk/build.mk.sample build.mk % vim mk/build.mk -- uncomment BuildFlavour = perf % autoreconf % perl boot % ./configure && make -j4 [stuff] % ./inplace/bin/ghc-stage2 binlist.hs -O2 [1 of 1] Compiling Main ( binlist.hs, binlist.o ) ghc-stage2: panic! (the 'impossible' happened) (GHC version 7.10.1.20150630 for x86_64-unknown-linux): Template variable unbound in rewrite rule sg_s5zd [sc_s5zb, sc_s5zc, sg_s5zd, sg_s5ze] [sc_s5zb, sc_s5zc, sg_s5zd, sg_s5ze] [: @ a_a3fj sc_s5zb sc_s5zc] [: @ a_a3fj sc_s5z7 sc_s5z8] }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10602#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler