CYGWIN_ROOT in abi_defs.mk

[Matti Picus]

My projects are stored at d:\matti\projects under windows.  My cygwin 
installation is located at c:\unix. I have my d drive mounted under /d so 
that    Lines 222-247 of abi_defs.mk define a TRANSFORM_TO_DOS_PATH macro 
that in my case foobars the build process. It turns
/d/matti/projects/abi
into
c:\\unix\\d\\matti\\projects\\abi

I do not know enough about sed and cygpath to fix this.  I have hardwired 
my copy of abi_defs.mk to fix this, but can someone suggest a better solution?

Matti