In JENKINS-5196 a new facility was added to make a "snapshot" before building.
It was specified that the name of the snapshot would use the name of the AccuRev stream as a prefix.
This wasn't done.

The current implementation uses the name of the Hudson project as a prefix.
This causes problems, as Hudson project names are not subject to the same limitations as AccuRev snapshot names.
e.g. a Hudson project name of "010_My_Project" built from AccuRev stream "MyProject", when combined with a build number of 1234 results in a snapshot name of "010_My_Project_1234" instead of "MyProject_1234".
This results in an error: Invalid stream name. Streams must begin with a non-digit other than "." and cannot contain the characters '\' or '/'

The snapshot name should be prefixed by the name of the accurev stream.
Given that AccuRev requires all names (within a depot) to be unique, I'd suggest that the snapshot ought to continue to include the hudson project name as well.

i.e. At present, the snapshot name is of the form

<HudsonProjectName>_<BuildNumber>

but it needs to be

<AccuRevStreamName>_<HudsonProjectName>_<BuildNumber>

(Ideally, it should be possible to configure the snapshot name to be a user-specified mix of stream/project/build and user strings, e.g. I'd like to have <AccuRevStreamName>_Source_<BuildNumber>, but that's another issue for another day)