The layers_.module.profile in testsuite/aggregator-preview only executes the testsuite/preview module. And then the web and smoke modules execute because they are enabled by default. This needs investigation.

Partly this may be due to an unclean distinction between ts.preview and ts.layers, where ts.preview partly functions as an analogue to standard WF's -DallTests, but for many modules the server is provisioned using layers under ts.preview while with -DallTests the already built complete thin server installation is used.