#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 thomie): Test still fails when `base` is compiled with -O2 (as it is in a perf or default/release build). {{{ $ make TEST=T10602 TEST_HC=ghc-7.10.1.20150710 ... =====> T10602(optasm) 92 of 92 [0, 0, 0] cd . && "/opt/ghc/7.10.2/bin/ghc-7.10.1.20150710" -c T10602.hs -fforce- recomp -dcore-lint -dcmm-lint -dno-debug-output -no-user-package-db -rtsopts -fno-warn-tabs -fno-ghci-history -O -fasm -O2 > T10602.comp.stderr 2>&1 Compile failed (status 256) errors were: ghc: panic! (the 'impossible' happened) (GHC version 7.10.1.20150710 for x86_64-unknown-linux): Template variable unbound in rewrite rule sg_s5zh [sc_s5zf, sc_s5zg, sg_s5zh, sg_s5zi] [sc_s5zf, sc_s5zg, sg_s5zh, sg_s5zi] [: @ a_a3fj sc_s5zf sc_s5zg] [: @ a_a3fj sc_s5zb sc_s5zc] }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10602#comment:15 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler