>The former is used to build a native compiler. The latter isn't. I know, but I got a long list of "unable to load dll" messages when compiling with x86_64-w64-mingw32. That doesn't happen when cross-compiling from x86_64-pc-msys. Those messages seem relatively harmless though? It doesn't say what dll is missing or if it breaks anything, but make doesn't count those as errors. >This looks relative to PR 70936. Possibly? Not sure. This is the include path for the temporary xg++ when invoked with the same command line as in the configure script: >$ echo | /home/JW/build-gcc-mingw64/./prev-gcc/xg++ -B/home/JW/build-gcc-mingw64/./prev-gcc/ -B/mingw64/x86_64-w64-mingw32/bin/ -nostdinc++ -B/home/JW/build-gcc-mingw64/prev-x86_64-w64-mingw32/libstdc++-v3/src/.libs -B/home/JW/build-gcc-mingw64/prev-x86_64-w64-mingw32/libstdc++-v3/libsupc++/.libs -I/home/JW/build-gcc-mingw64/prev-x86_64-w64-mingw32/libstdc++-v3/include/x86_64-w64-mingw32 -I/home/JW/build-gcc-mingw64/prev-x86_64-w64-mingw32/libstdc++-v3/include -I/home/JW/gcc-7.1.0/libstdc++-v3/libsupc++ -L/home/JW/build-gcc-mingw64/prev-x86_64-w64-mingw32/libstdc++-v3/src/.libs -L/home/JW/build-gcc-mingw64/prev-x86_64-w64-mingw32/libstdc++-v3/libsupc++/.libs -E -Wp,-v - >cc1.exe: warning: command line option '-nostdinc++' is valid for C++/ObjC++ but not for C ># 1 "<stdin>" ># 1 "<built-in>" ># 1 "<command-line>" ># 1 "<stdin>" >ignoring nonexistent directory "d:\msys64\home\jw\build-gcc-mingw64\prev-gcc\../lib/gcc/x86_64-w64-mingw32/7.1.0/include" >ignoring nonexistent directory "d:\msys64\home\jw\build-gcc-mingw64\prev-gcc\../lib/gcc/x86_64-w64-mingw32/7.1.0/../../../../include" >ignoring nonexistent directory "d:\msys64\home\jw\build-gcc-mingw64\prev-gcc\../lib/gcc/x86_64-w64-mingw32/7.1.0/include-fixed" >ignoring nonexistent directory "d:\msys64\home\jw\build-gcc-mingw64\prev-gcc\../lib/gcc/x86_64-w64-mingw32/7.1.0/../../../../x86_64-w64-mingw32/include" >ignoring nonexistent directory "d:/msys64/home/jw/build-gcc-mingw64/lib/gcc/x86_64-w64-mingw32/7.1.0/include" >ignoring nonexistent directory "/mingw64/include" >ignoring nonexistent directory "d:/msys64/home/jw/build-gcc-mingw64/lib/gcc/x86_64-w64-mingw32/7.1.0/include-fixed" >ignoring nonexistent directory "d:/msys64/home/jw/build-gcc-mingw64/x86_64-w64-mingw32/include" >ignoring nonexistent directory "/mingw/include" >#include "..." search starts here: >#include <...> search starts here: > D:/msys64/home/JW/build-gcc-mingw64/prev-x86_64-w64-mingw32/libstdc++-v3/include/x86_64-w64-mingw32 > D:/msys64/home/JW/build-gcc-mingw64/prev-x86_64-w64-mingw32/libstdc++-v3/include > D:/msys64/home/JW/gcc-7.1.0/libstdc++-v3/libsupc++ > D:/msys64/home/JW/build-gcc-mingw64/prev-gcc/include > D:/msys64/home/JW/build-gcc-mingw64/prev-gcc/include-fixed > D:/msys64/mingw64/lib/gcc/x86_64-w64-mingw32/7.1.0/../../../../include >End of search list. I called configure with "--with-native-system-header-dir=/mingw64/x86_64-w64-mingw32/include", so that's where it should be searching. But that doesn't appear anywhere in the search list. I suppose I could copy/link the system headers to one of the non-existent directories. Let's hope that doesn't break anything else...
