According to icinga, puppet has been critical on mw1 for about ten hours (as of writing this), with the failure: CRITICAL: Puppet has 1 failures. Last run 8 minutes ago with 1 failures. Failed resources (up to 3 shown): Exec[git_pull_MediaWiki config]. This would seem to indicate that any changes to mw-config are not going live on mw1, which can be confirmed through T2828 and T2817.
This error has popped up in the past, but has never lasted this long.