Problem in your project's configuration. Invalid configuration option "build.os": build not found

Command git submodule update --init --force --recursive docs/all-posts failed: Submodule 'docs/all-posts' (https://github.com/liuning0820/all-posts.git) registered for path 'docs/all-posts' Cloning into '/home/docs/checkouts/readthedocs.org/user_builds/doc-as-code-mkdocs-demo/checkouts/latest/docs/all-posts'... fatal: could not read Username for 'https://github.com': terminal prompts disabled fatal: clone of 'https://github.com/liuning0820/all-posts.git' into submodule path '/home/docs/checkouts/readthedocs.org/user_builds/doc-as-code-mkdocs-demo/checkouts/latest/docs/all-posts' failed Failed to clone 'docs/all-posts'. Retry scheduled Cloning into '/home/docs/checkouts/readthedocs.org/user_builds/doc-as-code-mkdocs-demo/checkouts/latest/docs/all-posts'... fatal: could not read Username for 'https://github.com': terminal prompts disabled fatal: clone of 'https://github.com/liuning0820/all-posts.git' into submodule path '/home/docs/checkouts/readthedocs.org/user_builds/doc-as-code-mkdocs-demo/checkouts/latest/docs/all-posts' failed Failed to clone 'docs/all-posts' a second time, aborting