I don't know the build system for this program (and this is a generic bug template so I cannot tell you which program exactly is), but my tests shows that it's not respecting CFLAGS properly. Please look into it, since it's important to respect user CFLAGS. Thanks, Diego
Created attachment 190691 [details, diff] patch to ebuild to apply patches I'm submitting
Created attachment 190693 [details, diff] patch to bzip2-1.0.2 to respect cflags and ldflags
Created attachment 190694 [details, diff] patch to bzip2-1.0.3 to respect cflags and ldflags
Created attachment 190695 [details, diff] patch to deltup-0.4.4 to compile with gcc-4.4, replaces patch to compile with gcc-4.3
Created attachment 190696 [details, diff] patch to deltup-0.4.4 to respect cflags, ldflags and --as-needed
replace files/ with my patches and patch the ebuild. This fixes bugs #240121, #246189 and #246916.
Fixed in portage, thanks for the patches!