I have just upgraded a couple of sites from an earlier release of SS3 to the 3.0 stable build (CMS & Sapphire). Now, when I try to dev/build I am getting the following error (the site was working fine pre dev/build but is now showing this error everywhere):

PHP Fatal error:  Uncaught exception 'SS_DAG_CyclicException' with message 'DAG has cyclic requirements' in /Users/fraser/Documents/Work/HallPass/sapphire/core/DAG.php:73
Stack trace:
#0 /Users/fraser/Documents/Work/HallPass/sapphire/core/manifest/ConfigManifest.php(272): SS_DAG->sort()
#1 /Users/fraser/Documents/Work/HallPass/sapphire/core/manifest/ConfigManifest.php(144): SS_ConfigManifest->sortYamlFragments()
#2 /Users/fraser/Documents/Work/HallPass/sapphire/core/manifest/ConfigManifest.php(75): SS_ConfigManifest->regenerate(false)
#3 /Users/fraser/Documents/Work/HallPass/sapphire/core/Core.php(275): SS_ConfigManifest->__construct('/Users/fraser/D...', false, false)
#4 /Users/fraser/Documents/Work/HallPass/sapphire/main.php(62): require_once('/Users/fraser/D...')
#5 {main}
  thrown in /Users/fraser/Documents/Work/HallPass/sapphire/core/DAG.php on line 73

Everything else works fine however, it's just when I do anything in /dev. I have made some changes and need to regenerate the manifest on these sites.

UPDATE: I have also tried a clean install of SS3 and am getting the same issue.

Any ideas?

Update.

I have just tried updating a 3rd site and am now getting the same error on this too.

For everyone elses reference - the ticket for this issue (solved for the upcoming 3.0.2) is at http://open.silverstripe.org/ticket/7817 with explaination.