The error message says that you much pick a file in order for the configuration to work. Specifically it must be a file containing the func main() declaration.
You can use the Run Type: Package instead of file in order to run a package.
For example, if your main is under $GOPATH/src/github.com/dlsniper/demo/cmd/mycmd/main.go then you need to use github.com/dlsniper/demo/cmd/mycmd in order to run it.
Moreover, from the screenshot you've pasted, it seems like you are not under a valid Go workspace. Please see here what a Go Workspace is and how to create one: https://golang.org/doc/code.html#Workspaces
Finally, if you prefer a visual guide for this, please have a look at this video on how to create and use Run Configurations in Gogland: https://www.youtube.com/watch?v=ko-wKntCLjg
The error message says that you much pick a file in order for the configuration to work. Specifically it must be a file containing the
func main()declaration.You can use the Run Type: Package instead of file in order to run a package.
For example, if your main is under
$GOPATH/src/github.com/dlsniper/demo/cmd/mycmd/main.gothen you need to usegithub.com/dlsniper/demo/cmd/mycmdin order to run it.Moreover, from the screenshot you've pasted, it seems like you are not under a valid Go workspace. Please see here what a Go Workspace is and how to create one: https://golang.org/doc/code.html#Workspaces
Finally, if you prefer a visual guide for this, please have a look at this video on how to create and use Run Configurations in Gogland: https://www.youtube.com/watch?v=ko-wKntCLjg