It appears that the hydro rosdistro cache has non safe_load-able YAML entries. ``` wget http://repositories.ros.org/rosdistro_cache/hydro-cache.yaml.gz --2019-02-14 17:40:14-- http://repositories.ros.org/rosdistro_cache/hydro-cache.yaml.gz Resolving repositories.ros.org (repositories.ros.org)... 52.53.127.253 Connecting to repositories.ros.org (repositories.ros.org)|52.53.127.253|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 325081 (317K) [application/x-gzip] Saving to: hydro-cache.yaml.gz hydro-cache.yaml.gz 100%[============================================================>] 317.46K --.-KB/s in 0.08s 2019-02-14 17:40:14 (4.06 MB/s) - hydro-cache.yaml.gz saved [325081/325081] steven@octobeast:~[127] gunzip hydro-cache.yaml.gz steven@octobeast:~ grep ar_sys hydro-cache.yaml ar_sys: doc: {type: git, url: 'https://github.com/Sahloul/ar_sys.git', version: hydro-devel} source: {type: git, url: 'https://github.com/Sahloul/ar_sys.git', version: hydro-devel} \n", ar_sys: !!python/str "\n\n\tar_sys\n\ >http://wiki.ros.org/ar_sys\n\t