Failure to make sitl on Winodws

I’m trying to build the ArduCopter by following the instructions here:
On the make sitl -j4 step, errors occur…

Merged enum MAV_CMD
Found 176 MAVLink message types in 2 XML files
Generating C implementation in directory /tmp/ Link/include/mavlink/v1.0/ardupilotmega
Generating C implementation in directory /tmp/ Link/include/mavlink/v1.0/common
Copying fixed headers
C:/cygwin/home/derek/ardupilot/mk/ recipe for target ‘/tmp/ArduCopte’ fail ed
make: *** [/tmp/ pilotmega/mavlink.h] Aborted (core dumped)
make: *** Deleting file ‘/tmp/ link/v1.0/ardupilotmega/mavlink.h’

I’m stuck… any suggestion for how to get this to build or look for errors?
I’ve rebuild the tool chain twice in different locations and get the same error ;(
Thanks in advance for any help you can provide.

I am also having this issue as well.

That makes at least 5 of us… What you describe looks to be the same symptoms that myself and two others are experiencing:

Major problem when installing “SITL” on Windows

NB: this was raised as issue 3586 on the project’s github page. There is a workaround posted there that you can use to get SITL working again.