Re: possible race condition (fetch-pack: unexpected disconnect while reading sideband packet)

From: Jeff King <peff@peff.net>
Date: Apr 15, 2021, 08:29 UTC
Message-ID: <YHf5bkiE7SVPTBvU@coredump.intra.peff.net>
In-Reply-To: <df13300936784af7bb6c23f9fe0465c9@digiteqautomotive.com>

On Wed, Apr 14, 2021 at 10:12:44AM +0000, Simon, Martin (Digiteq Automotive) wrote:

Show 8 quoted lines

> Actual result (when failed):
> Cloning into 'local-repo-name'...
> remote: Enumerating objects: 237, done.
> remote: Counting objects: 100% (237/237), done.
> remote: Compressing objects: 100% (129/129), done.
> fetch-pack: unexpected disconnect while reading sideband packet
> fatal: early EOF
> fatal: fetch-pack: invalid index-pack output

This could be many things. A bug or race on the client side is possible, but it could also be that the network session really _is_ being disconnected. This could be something in the network stack itself terminating the connection, or it could be a bug or other error on the server.

Some things to consider/try:

  - you can run with GIT_TRACE_PACKET=1 set in the environment, which
    will dump the protocol messages that Git sees (this may not be
    enlightening since the problem case seems to be a hangup, but
    perhaps the moment it happens will be relevant)

  - you didn't say which protocol you're using. If it's http, try
    setting GIT_TRACE_CURL, too, and it will dump debugging data about
    the http session

  - if possible, try a different protocol (like ssh) and see if the
    problem continues to show up

  - look at server-side logs to see how the server perceives the
    sessions. Does it report any errors that might cause it to hang up?
    Does it see a client-side hangup (which might be indicative of
    something flaky in the network)?

-Peff