Fix

The error occurs because every Go file in the directory has build constraints that exclude the current operating system or architecture. Add a file without constraints or remove the constraints from existing files.

//go:build !windows
// +build !windows

package main

func main() {
    // This file is excluded on Windows
}

To fix it, ensure at least one file in the package has no build constraints or a constraint that matches your environment (e.g., remove //go:build ignore or //go:build !linux if you are on Linux).

Go ignores files that have rules saying "do not use me on this computer." If every file in your folder has such a rule for your specific machine, Go thinks the folder is empty and throws this error. You need to remove the rule from at least one file so Go knows it can use it.