[users at bb.net] 0.8.x: configuring Force scheduler to force clean build?

[Stephen Davis]

For speed of commit -> failure turnaround, my builds are configured to use mode="incremental".

However, on occasion, some weird build artifact creeps in and the build gets stuck in a bad state.  I'd like to configure the Force scheduler to override the "mode" property of the source step so I can force a clean build but I can't figure out how to do it from the docs at https://docs.buildbot.net/0.8.14/developer/cls-forcesched.html?highlight=force.

The current force scheduler config looks like:

schedulers.append( ForceScheduler(	name = "force",
									
									# list of builder names which can be forced
									builderNames = names,

									# user specifies the reason
									reason = StringParameter( name="reason", label="reason:<br>", required=True, size=80 ),

									# will generate nothing in the form, but revision, repository,
									# and project are needed by buildbot scheduling system so we
									# need to pass a value ("")
									branch = FixedParameter( name="branch", default="" ),
									revision = FixedParameter( name="revision", default="" ),
									repository = FixedParameter( name="repository", default="" ),
									project = FixedParameter( name="project", default="" ),
								) )

What I'd like is to force the source update steps to use "full" or "clobber" mode but that doesn't seem possible.  Is there some other option that can be set to force a fresh build on the buildslave?

thanks,
stephen