Building a MobileFirst project that has an "adapters" folder in the "common" environment, causes a build error: "Adapter deployment failed: Adapter 'xxx' contains errors ". I guess the build system is looking for an "adapters" folder anywhere (and should only look in the root).
Thanks for the report. The development team will investigate. There is obviously no workaround... Other than using a different name for the folder.
If you'll want a fix for this issue you'll need to one a PMR support ticket.