Volume Mount Error When GOPATH Contains Multiple Values

[cwarden]

If GOPATH contains multiple colon-separated paths, xgo fails because the bind mount is invalid.

For example, the default GOPATH in CircleCI's ubuntu-2204:2023.07.2 machine image is /home/circleci/.go_workspace:/usr/local/go_workspace. xgo generates a parameter to docker of -v /home/circleci/.go_workspace:/usr/local/go_workspace:/go, resulting in a error, docker: Error response from daemon: invalid mode: /go.