Make use of original working copy the default Also use shared working copy if original working copy cannot be used. These two options has been used (by JV) for more than a year and seem to work fine.

pushd common
call mingwmake.bat %1 %2 %3 %4 %5 %6 %7 %8 %9
popd 
pushd mercurial
call mingwmake.bat %1 %2 %3 %4 %5 %6 %7 %8 %9
popd