Implement gitlab:

def _rewrite_url(url, branch=None):
    if not branch:
        branch = "HEAD"
    if url.startswith("github:"):
        url = url[7:].split("/")
        url = (
            "https://raw.githubusercontent.com/"
            + url[0]
            + "/"
            + url[1]
            + "/"
            + branch
            + "/"
            + "/".join(url[2:])
        )
    if url.startswith("gitlab:"):
        url = url[7:].split("/")
        url = (
            "https://gitlab.com/"
            + url[0]
            + "/"
            + url[1]
            + "/-/raw/"
            + branch
            + "/"
            + "/".join(url[2:])
        )
    return url

#...


def _install_package(package, index, target, version, mpy):
    if (
        package.startswith("http://")
        or package.startswith("https://")
        or package.startswith("github:")
        or package.startswith("gitlab:")
    ):
#...