I tried to build cygwin from sources. As FAQ suggests I used --without-cross-bootstrap option to configure to build without using mingw64-x86_64-gcc-g++. It turns out this option works in opposite. I used --with-cross-bootstrap option and build went successfully. But that's a bug, I think.
In file winsup/configure.ac snippet below uses inverted logic: if test "x$with_cross_bootstrap" != "xyes"; then AC_CHECK_PROGS(MINGW_CXX, ${target_cpu}-w64-mingw32-g++) test -n "$MINGW_CXX" || AC_MSG_ERROR([no acceptable MinGW g++ found in \$PATH]) AC_CHECK_PROGS(MINGW_CC, ${target_cpu}-w64-mingw32-gcc) test -n "$MINGW_CC" || AC_MSG_ERROR([no acceptable MinGW gcc found in \$PATH]) fi AM_CONDITIONAL(CROSS_BOOTSTRAP, [test "x$with_cross_bootstrap" != "xyes"]) I think it should be: if test "x$with_cross_bootstrap" = "xyes"; then ... AM_CONDITIONAL(CROSS_BOOTSTRAP, [test "x$with_cross_bootstrap" = "xyes"]) And I think help message should be changed as well. AC_ARG_WITH([cross-bootstrap],[AS_HELP_STRING([--with-cross-bootstrap],[do not build programs using the MinGW toolchain or check for MinGW libraries (useful for bootstrapping a cross-compiler)])],[],[with_cross_bootstrap=no]) to: AC_ARG_WITH([cross-bootstrap],[AS_HELP_STRING([--without-cross-bootstrap],[do not build programs using the MinGW toolchain or check for MinGW libraries (useful for bootstrapping a cross-compiler)])],[],[with_cross_bootstrap=no]) Though, I'm not an expert. All this was found through experimentation. -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple