tor 0.2.5 does not build on s390 with picky gcc
5:31:08 depbase=`echo src/common/backtrace.o | sed 's|[^/]*$|.deps/&|;s|\.o$||'`;\
15:31:08 gcc -DHAVE_CONFIG_H -I. -I../tor -I../tor/src/ext -Isrc/ext -I../tor/src/common -Isrc/common -I../tor/src/or -Isrc/or -DSHARE_DATADIR="\"/usr/local/share\"" -DLOCALSTATEDIR="\"/usr/local/var\"" -DBINDIR="\"/usr/local/bin\"" -I../tor/src/common -g -O2 -D_FORTIFY_SOURCE=2 -fstack-protector-all -Wstack-protector -fwrapv --param ssp-buffer-size=1 -fPIE -fasynchronous-unwind-tables -Wall -fno-strict-aliasing -W -Wfloat-equal -Wundef -Wpointer-arith -Wstrict-prototypes -Wmissing-prototypes -Wwrite-strings -Wredundant-decls -Wchar-subscripts -Wcomment -Wformat=2 -Wwrite-strings -Wmissing-declarations -Wredundant-decls -Wnested-externs -Wbad-function-cast -Wswitch-enum -Werror -Winit-self -Wmissing-field-initializers -Wdeclaration-after-statement -Wold-style-definition -Waddress -Wmissing-noreturn -Wstrict-overflow=1 -Wnormalized=id -Woverride-init -Wextra -Warray-bounds -Wlogical-op -MT src/common/backtrace.o -MD -MP -MF $depbase.Tpo -c -o src/common/backtrace.o ../tor/src/common/backtrace.c &&\
15:31:08 mv -f $depbase.Tpo $depbase.Po
15:31:11 ../tor/src/common/backtrace.c: In function 'clean_backtrace':
15:31:11 ../tor/src/common/backtrace.c:65:24: error: unused parameter 'stack' [-Werror=unused-parameter]
15:31:11 clean_backtrace(void **stack, int depth, const ucontext_t *ctx)
15:31:11 ^
15:31:14 cc1: all warnings being treated as errors
15:31:14 Makefile:2365: recipe for target 'src/common/backtrace.o' failed
15:31:14 make[1]: *** [src/common/backtrace.o] Error 1