(In reply to comment #7)
> Just happened to me w/operations/puppet.
> 
> $ git pull
> hash mismatch
> key_verify failed for server_host_key
> fatal: Could not read from remote repository.
> 
> Please make sure you have the correct access rights
> and the repository exists.

We see similar errors very regularly when updating 600 or so extension repos at translatewiki.net. I'm pretty certain that we have the correct access rights with L10n-bot, have the correct access rights at the local machine, and have consistent scripting up update the repos.

A run I did just now resulted in the following errors:

Permission denied (publickey).
fatal: The remote end hung up unexpectedly
error: Could not fetch origin
/resources/siebrand/mediawiki-extensions/extensions/CategoryMagicWords failed to update

Permission denied (publickey).
fatal: The remote end hung up unexpectedly
error: Could not fetch origin
/resources/siebrand/mediawiki-extensions/extensions/ReplaceSet failed to update

Just to make sure that it wasn't me configuring the two above repos incorrectly, I ran the updates again. This time with the following result:

Permission denied (publickey).
fatal: The remote end hung up unexpectedly
error: Could not fetch origin
/resources/siebrand/mediawiki-extensions/extensions/DidYouKnow failed to update

Permission denied (publickey).
fatal: The remote end hung up unexpectedly
error: Could not fetch gerrit
/resources/siebrand/mediawiki-extensions/extensions/FormatDates failed to update

Permission denied (publickey).
fatal: The remote end hung up unexpectedly
error: Could not fetch gerrit
/resources/siebrand/mediawiki-extensions/extensions/GoogleDocTag failed to update

Permission denied (publickey).
fatal: The remote end hung up unexpectedly
error: Could not fetch origin
/resources/siebrand/mediawiki-extensions/extensions/InviteSignup failed to update

Permission denied (publickey).
fatal: The remote end hung up unexpectedly
error: Could not fetch origin
/resources/siebrand/mediawiki-extensions/extensions/LightweightRDFa failed to update

Permission denied (publickey).
fatal: The remote end hung up unexpectedly
error: Could not fetch origin
Permission denied (publickey).
fatal: The remote end hung up unexpectedly
error: Could not fetch gerrit
/resources/siebrand/mediawiki-extensions/extensions/Numbertext failed to update

/resources/siebrand/mediawiki-extensions/extensions/NumberOfWikis failed to update

Permission denied (publickey).
fatal: The remote end hung up unexpectedly
error: Could not fetch gerrit
/resources/siebrand/mediawiki-extensions/extensions/PageLanguage failed to update

Permission denied (publickey).
fatal: The remote end hung up unexpectedly
error: Could not fetch origin
/resources/siebrand/mediawiki-extensions/extensions/SidebarDonateBox failed to update

hash mismatch
key_verify failed for server_host_key
fatal: The remote end hung up unexpectedly
error: Could not fetch gerrit
/resources/siebrand/mediawiki-extensions/extensions/UserStatus failed to update

Permission denied (publickey).
fatal: The remote end hung up unexpectedly
error: Could not fetch gerrit
/resources/siebrand/mediawiki-extensions/extensions/VersionView failed to update



To compare, when updating repos on localhost form GitHub, I've not seen a similar error once.