For future reference, this was happening because the application attempting to be built was including an imported deployable, and there was no active build in the referenced application. The error message will be clarified in the next version of BuildMaster (v3.2.2).

BuildMaster is not a build tool in the same sense as make, Rake, Ant, NAnt, etc. However, BuildMaster will integrate with an ever-growing list (http://inedo.com/buildmaster/integration) of build tools to manage your build throughout its release lifecycle by providing an automated deployment mechanism that enhances repeatability, auditing, and maintainability.

There may be a number of reasons why a builds aren't being created: Verify that there are releases for the target applications; a build cannot be created unless a release exists. Make sure the build schedule (under each app) is there, and not set to "disabled." Verify that the service is running. (Admin -> Service) Look for entries in the error log (Admin -> Errors) to see if anything popped up overnight. Verify that the ScheduleExecuterThrottle (Admin -> Advanced Settings) is a positive integer (default is 1).

If the service is still running, or was restarted and the same pending behavior persists this situation can also indicate that buildmaster's database has run out of disk space.