Comment 8 for bug 2036268

Building using the -funwind-tables flag without stripping the default mbranch-protection as in 1:2.3.16+dfsg1-3 version doesn't work.:

CFLAGS ......... : -std=gnu99 -g -O2 -ffile-prefix-map=/<<PKGBUILDDIR>>=. -flto=auto -ffat-lto-objects -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -mbranch-protection=standard -fdebug-prefix-map=/<<PKGBUILDDIR>>=/usr/src/dovecot-1:2.3.20+dfsg1-1ubuntu3+ppa2 -funwind-tables -fstack-protector-strong -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3 -Wall -W -Wmissing-prototypes -Wmissing-declarations -Wpointer-arith -Wchar-subscripts -Wformat=2 -Wbad-function-cast -fno-builtin-strftime -Wstrict-aliasing=2

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gcc -DHAVE_CONFIG_H -I. -I../.. -I../../src/lib-test -Wdate-time -D_FORTIFY_SOURCE=2 -std=gnu99 -g -O2 -ffile-prefix-map=/<<PKGBUILDDIR>>=. -flto=auto -ffat-lto-objects -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -mbranch-protection=standard -fdebug-prefix-map=/<<PKGBUILDDIR>>=/usr/src/dovecot-1:2.3.20+dfsg1-1ubuntu3+ppa2 -funwind-tables -fstack-protector-strong -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3 -Wall -W -Wmissing-prototypes -Wmissing-declarations -Wpointer-arith -Wchar-subscripts -Wformat=2 -Wbad-function-cast -fno-builtin-strftime -Wstrict-aliasing=2 -c -o test_lib-test-backtrace.o `test -f 'test-backtrace.c' || echo './'`test-backtrace.c

[...]

test-backtrace.c:14: Assert failed: strstr(str_c(bt), "test_backtrace") != NULL
backtrace_append ..................................................... : FAILED
test-backtrace.c:38: Assert failed: strstr(bt, "test_backtrace") != NULL
backtrace_get ........................................................ : FAILED