A command determines whether it is in a workspace context by first examining the GOWORK environment variable. If GOWORK is set to off, the command will be in a single-module context. If it is empty or not provided, the command will search the current working directory, and then successive parent directories, for a file go.work. If a file is found, the command will operate in the workspace it defines; otherwise, the workspace will include only the module containing the working directory. If GOWORK names a path to an existing file that ends in .work, workspace mode will be enabled. Any other value is an error. You can use the go env GOWORK command to determine which go.work file the go command is using. go env GOWORK will be empty if the go command is not in workspace mode.