Trying to build samba 4.0.0beta1 with --bundled-libraries=NONE :
Checking for system tdb >= 2.0.0: not found
ERROR: System library tdb of version 2.0.0 not found, and bundling disabled
And bundling things is not nice. Please try to provide a tdb-2 tarball (a release candidate / beta would be ok too)
Fixed in subsequent versions.