For example, expat's configure reads: { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5 $as_echo "$as_me: error: in \`$ac_pwd':" >&2;} as_fn_error $? "C++ preprocessor \"$CXXCPP\" fails sanity check See \`config.log' for more details" "$LINENO" 5; } which doesn't match the code in patch. Therefore, epunt_cxx fails. This triggered a lot of QA warnings which resulted in bug reports which were misinterpreted, so I disabled the warning temporarily.
Reminder for myself. Might need to revert this for sysfsutils & expat wrt bug 460786 and bug 460782.
http://sources.gentoo.org/eclass/eutils.eclass?r1=1.414&r2=1.415 http://sources.gentoo.org/eclass/ELT-patches/nocxx/nocxx-2.64.patch?rev=1.1