James HAUXWELL wrote: > $ ./configure '--enable-languages=c' --enable-threads=posix You're building inside the source directory. That's not supported and may break in strange ways. You should build in a completely separate build directory that is not a subdirectory of the source tree. And give the full path to configure when configuring. This is explained in the installation directions. > $ gcc pestoes.c -mno-cygwin -v pestoes.exe You built a Cygwin compiler but now you're asking it to use the mingw compiler... > gcc: error trying to exec 'cc1': execvp: No such file or directory ...which does not exist. If you want to use a mingw compiler you will have to build one (--target=mingw32). If you want a Cygwin compiler that has a working -mno-cygwin you will have to build both a Cygwin gcc and a mingw gcc and install them in the same tree. You may have to tweak the specs file as well. If your end goal is a mingw compiler then just build one and call it directly, instead of trying to use -mno-cygwin. Brian