The tooling API sometimes returns buildSrc as a project and in other cases it does not. To the chagrin of some users who find this illogical / inconsistent.
A bug has been reported agains STS here:
See that issue for details.
I could implement a workaround in STS to ignore buildSrc when returned by tooling API but I feel this is really a problem with the tooling API implementation rather than the tooling so it should be fixed ‘at source’.
Is that reasonable? Or is there in fact a good reason why the buildSrc project is returned in some cases whereas its not in others?