Using the commandline:

Code
make -j9 NOWERROR=1 PTR64=1 sse4=1 USE_NETWORK=1

I get the following when it tries to link the executable:

Code
Linking mame64.exe...
../../../../mingw-gcc/bin/x64/Release/mame_mame/libseibu.a: file not recognized: File format not recognized
collect2.exe: error: ld returned 1 exit status
mame.make:228: recipe for target '../../../../../mame64.exe' failed
make[2]: *** [../../../../../mame64.exe] Error 1
Makefile:952: recipe for target 'mame' failed
make[1]: *** [mame] Error 2
makefile:847: recipe for target 'windows_x64' failed
make: *** [windows_x64] Error 2

Any ideas?