id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
5111	linux-powerpc : segfault in stage2 compiler	erikd		"After the patch to fix #4999, the compile gets a bit further and now crashes at:

{{{
""inplace/bin/ghc-stage2""   -H32m -O    -package-name vector-0.7.0.1 -hide-all-packages -i -ilibraries/vector/. -ilibraries/vector/dist-install/build -ilibraries/vector/dist-install/build/autogen -Ilibraries/vector/dist-install/build -Ilibraries/vector/dist-install/build/autogen -Ilibraries/vector/include -Ilibraries/vector/internal   -optP-DVECTOR_BOUNDS_CHECKS -optP-include -optPlibraries/vector/dist-install/build/autogen/cabal_macros.h -package base-4.3.1.0 -package primitive-0.3.1  -O2 -XHaskell98 -XCPP -XDeriveDataTypeable -O2 -XGenerics -no-user-package-conf -rtsopts     -odir libraries/vector/dist-install/build -hidir libraries/vector/dist-install/build -stubdir libraries/vector/dist-install/build -hisuf hi -osuf  o -hcsuf hc -c libraries/vector/./Data/Vector/Fusion/Stream/Monadic.hs -o libraries/vector/dist-install/build/Data/Vector/Fusion/Stream/Monadic.o
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Loading package primitive-0.3.1 ... linking ... done.
Loading package ffi-1.0 ... linking ... done.
Segmentation fault
make[1]: *** [libraries/vector/dist-install/build/Data/Vector/Fusion/Stream/Monadic.o] Error 139
make: *** [all] Error 2
}}}

Compiling with debug on and running under gdb results in:

{{{
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Loading package primitive-0.3.1 ... linking ... done.
Loading package ffi-1.0 ... linking ... done.

Program received signal SIGSEGV, Segmentation fault.
0xf19ea004 in ?? ()
(gdb) bt
#0  0xf19ea004 in ?? ()
#1  0x11a30f58 in schedule (initialCapability=0x93fb0070, task=0x3dc0f1de) at rts/Schedule.c:457
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
}}}

so this is crashing in haskell code, not the RTS.

Tracing this using putStr and friends I've tracked the bug to TcSplice.runMeta. It seems to crash when a thunk is evaluated just as that function returns. I'm still working on tracing back from there.

"	bug	closed	normal	_|_	Compiler	7.1	duplicate		pho@…	Linux	powerpc	Installing GHC failed