#10602: ghc panic: Template variable unbound in rewrite rule when compiling with -O2 -------------------------------------+------------------------------------- Reporter: pacak | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.10.2 Component: Compiler | Version: 7.10.2-rc2 Resolution: | Keywords: Operating System: Linux | Architecture: Type of failure: Compile-time | Unknown/Multiple crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Description changed by goldfire: Old description:

I've seen a few related tickets, but they are market as closed.

% ghc -O2 binlist.hs

[1 of 1] Compiling Main ( binlist.hs, binlist.o ) ghc: panic! (the 'impossible' happened) (GHC version 7.10.1.20150630 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_a3fo sc_s5zf sc_s5zg] [: @ a_a3fo sc_s5zb sc_s5zc]

Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug

% cat binlist.hs import Control.Monad import Data.Binary import Data.List

newtype A a = A [a]

instance Binary a => Binary (A a) where put (A xs) = case splitAt 254 xs of (_, []) -> mapM_ put xs (a, b) -> put (A b)

get = do xs <- replicateM 254 get A ys <- get return $ A $ xs ++ ys

main :: IO () main = undefined

New description: I've seen a few related tickets, but they are market as closed. {{{ % ghc -O2 binlist.hs [1 of 1] Compiling Main ( binlist.hs, binlist.o ) ghc: panic! (the 'impossible' happened) (GHC version 7.10.1.20150630 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_a3fo sc_s5zf sc_s5zg] [: @ a_a3fo sc_s5zb sc_s5zc] Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug % cat binlist.hs import Control.Monad import Data.Binary import Data.List newtype A a = A [a] instance Binary a => Binary (A a) where put (A xs) = case splitAt 254 xs of (_, []) -> mapM_ put xs (a, b) -> put (A b) get = do xs <- replicateM 254 get A ys <- get return $ A $ xs ++ ys main :: IO () main = undefined }}} -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10602#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10602: ghc panic: Template variable unbound in rewrite rule when compiling with -O2 -------------------------------------+------------------------------------- Reporter: pacak | Owner: bgamari Type: bug | Status: new 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: -------------------------------------+------------------------------------- Changes (by bgamari): * owner: => bgamari Comment: Oh dear. I'll have a look. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10602#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#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: -------------------------------------+------------------------------------- Changes (by bgamari): * status: new => infoneeded -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10602#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#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): rc2 downloaded from ghc website as {{{ghc-7.10.1.20150630-src.tar.xz}}} {{{ % cat mk/build.mk GhcRTSWays += debug GhcRTSWays += debug_p GhcRTSWays += thr_debug GhcRTSWays += thr_debug_p BUILD_DOCBOOK_HTML = YES DYNAMIC_GHC_PROGRAMS = NO }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10602#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#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 goldfire): I observed the failure with 7.10.2-rc1 (7.10.1.20150612). I forget if I built it myself or downloaded from somewhere. I don't have more recent builds to hand. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10602#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#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 bgamari): Indeed I have reproduced this. Previously I missed that `-O2` was necessary; I believe I was just using `-O` previously. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10602#comment:11 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#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 goldfire): If it's working in HEAD and at the tip of the ghc-7.10 branch, I think it's safe to close the ticket with a regression test. Given the sensitivity of the bug, it might be worth the trouble to make sure that the regression test actually fails on, say, 7.10.2-rc1. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10602#comment:13 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#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

#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 bgamari): Hmm, this is very odd. thomie, I suppose your alternate test case still on reproduces with the `ghc-stage2` binary? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10602#comment:17 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#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 simonpj): OK I'm on it. Thank you for a simple repro case. Simon -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10602#comment:19 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10602: ghc panic: Template variable unbound in rewrite rule when compiling with -O2 -------------------------------------+------------------------------------- Reporter: pacak | Owner: bgamari Type: bug | Status: closed Priority: highest | Milestone: 7.10.2 Component: Compiler | Version: 7.10.2-rc2 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash | Test Case: Blocked By: | simplCore/should_compile/T10602 Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Changes (by bgamari): * status: merge => closed * resolution: => fixed Comment: Merged to `ghc-7.10` in 3cadf440c490abc1c8d5d45f5d034809c8912815. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10602#comment:21 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler