promotes antipattern of building individual go files

[seankhliao]

In general, the go tool operates on packages (directories) rather than individual go files.
While allowed, commands like go build main.go are more of a special case and introduces various issues like golang/go#51279 because it is using a virtual synthesized package.

This action promotes the antipattern of operating on a singular main file by asking for "the path of a build target (a file with a main() function)" as the input to go-build-target. It should ask for a package path instead.