Fixing "Cannot Find Package" Error in Go Build

When working with Go, developers may encounter the "Cannot find package" error when executing "go build" or "go run" commands. Despite setting GOPATH, the error persists, hindering package discovery. To address this issue, it's crucial to understand the expected package directory structure.

Understanding the Package Directory Structure

Go expects packages to reside in directories with the same name as their package names. When importing a package, the "import" statement specifies the package name, not the source file name. Therefore, in your example, foobar.go should be placed in $GOPATH/src/foobar/.

Solution

1. Move foobar.go: Relocate foobar.go to $GOPATH/src/foobar/foobar.go.
2. Configure PATH (Recommended): Add $GOPATH/bin to your PATH environment variable to access Go binaries conveniently.

Additional Recommendations

To enhance your Go development workflow, consider the following:

1. Organize Your Code: Place main.go in a subfolder under $GOPATH/src to better organize your projects.
2. Use "go install": Execute "go install test" (assuming your project is now in $GOPATH/src/test/) to install the executable in $GOPATH/bin, allowing you to run it directly from the terminal.