Need help on building Mesa3D 11.0.3 (PLEASE REPLY)

Hi people, too make a long reading short, am currently trying to build Mesa3D version 11.0.3
when executing “scons.py” in MinGW (assuming everything is ready) i always get “usr/bin/env: python: no such file or directory”
Any ideas why this happens? Any recommendations or repairs or anything helpful?
Thanks in advance!