Xcode 10: A valid provisioning profile for this executable was not found

I was struggling with this today, it was super frustrating. For now, just go into "File" > "Project Settings..." (or in some cases "Workspace Settings..." ) and then select "Legacy Build System" from the "Build System" dropdown.

Just in case you havent created a provisioning profile yet if there is a existing provisioning profile then just download it, follow the next tutorial, hope this help.