The script file for buckminster needs to be compliant with the unix/linux shell
syntax. The \ is treated as escape character during interpretion which causes
windows-like paths like
file:///c:\hudson\jobs\rcp_target\workspace/com.example.target/target.mspec
to be transformed into
import 'file:///c:hudsonjobscp_targetworkspace/com.example.target/target.mspec'

For the full discussion and more information see:
http://www.eclipse.org/forums/index.php?t=msg&th=158252&start=0&S=7a7c602cb92ec9f9c89daf19c18ec658
and
https://bugs.eclipse.org/bugs/show_bug.cgi?id=296081