Hi there,
I have set up a build job that uses CVS as its SCM. Specifically, it polls a
specific TAG in cvs, and then builds if changes are detected.

Here are relevant configuration information:
Source Control Management
CVS: (selected)
Branch: (my tag name)
This is a tag, not a branch: (checked)

Build Triggers
Poll SCM: (checked)
Schedule: */5 * * * *

It seems like with this configuration, the build gets triggered every 5
minutes, even when there are no changes to the CVS repository. The following is
in the polling log:
Workspace is inconsistent with configuration. Scheduling a new build
...

In investigating further, I found that the problem seems to be because when a
particular tag (instead of branch) of a module is checked out from CVS, the
contents of the CVS/Tag files is:
N<tagname>

instead of
T<tagname>

Changing the "isUpdatableModule(File)" method in hudson.scm.CVSSCM class in the
core Hudson library as follows seem to resolve the issue:

From:
...
if(branch!=null)

{ if(!checkContents(new File(cvs,"Tag"),'T'+branch)) return false; }

...
...

To:
...
if(branch!=null) {
if(isTag)

{ if(!checkContents(new File(cvs,"Tag"),'N'+branch)) return false; }

else

{ if(!checkContents(new File(cvs,"Tag"),'T'+branch)) return false; }

} ...
...

Thank you!