I have confirmed on Win7 that the following 32bit MinGW flavors still recognize -mno-cygwin option and build without error:

(4.5.2) http://tdm-gcc.tdragon.net/download

(4.5.4) http://sourceforge.net/projects/mingw-w64/files/Toolchains%20targetting%20Win32/Automated%20Builds/ using the mingw-w32-1.0-bin_i686-mingw_20110624.zip download

...by compiling with:

[i686-w64-mingw32-]gcc -Wall -mno-cygwin -o helloworld.exe helloworld.c

...where helloworld.c was:

#include <stdio.h>
int main(int argc, char *argv[]) { printf("Hello World!\n"); return 0; }


I have not yet checked the latest mingw.org download from the following, but I expect that it also recognizes -mno-cygwin. I will check later and report back if appropriate.

(4.5.2) http://sourceforge.net/projects/mingw/files/

Given Ruben's 4.4 comment, something is odd here. Looks like some gcc source spelunking as these doc links make no mention of the removal:

http://gcc.gnu.org/gcc-4.6/changes.html
http://gcc.gnu.org/gcc-4.5/changes.html
http://gcc.gnu.org/gcc-4.4/changes.html

and the gcc manual is inconsistent. This summary mentions the option

http://gcc.gnu.org/onlinedocs/gcc-4.6.1/gcc/Option-Summary.html#Option-Summary

but the details sections don't mention the option

http://gcc.gnu.org/onlinedocs/gcc-4.6.1/gcc/i386-and-x86_002d64-Windows-Options.html#i386-and-x86_002d64-Windows-Options

http://gcc.gnu.org/onlinedocs/gcc-4.6.1/gcc/i386-and-x86_002d64-Options.html#i386-and-x86_002d64-Options

Ah, our good friend grep.