Control: tags -1 + patch I found the documentation of the optimization flags for GCC 7.2.0 [1]. I was then able to bisect the list of flags enabled for -O2 and determine which ones needed to be disabled in order to build htslib on i386. Patch follows.
--- a/debian/rules +++ b/debian/rules @@ -7,7 +7,9 @@ include /usr/share/dpkg/default.mk -export DEB_CFLAGS_MAINT_APPEND = -fno-strict-aliasing +ifneq (,$(filter $(DEB_HOST_ARCH),i386)) + export DEB_CFLAGS_MAINT_APPEND=-fno-strict-aliasing -fno-code-hoisting +endif %: [1] https://gcc.gnu.org/onlinedocs/gcc-7.2.0/gcc/Optimize-Options.html