Fixing Git remote end hung up unexpectedly during push

What this error means

Git prints "The remote end hung up unexpectedly" when the server closes the connection mid-operation (push, fetch, or clone). Common root causes:

• Network or proxy issues (HTTP/2 quirks, SSL interception, timeouts)
• Large pushes (huge packfiles, binaries not using LFS)
• Authentication or credential problems
• Server-side hooks or quotas rejecting the update

This guide focuses on practical DevOps troubleshooting for pushes.

Quickstart: most common fixes

Try these in order (stop when the push succeeds):

• Reduce protocol quirks (HTTP remotes):
  • git config --global http.version HTTP/1.1
  • git config --global http.expectContinue false
• Remove broken proxy settings:
  • git config --global --unset http.proxy
  • unset HTTPS_PROXY https_proxy HTTP_PROXY http_proxy
• Re-authenticate:
  • For HTTPS: update your credential helper or token
  • For SSH: ssh -T git@your-host and refresh keys/agent
• Avoid huge packfiles:
  • Commit smaller batches, or use Git LFS for large binaries
• Gather diagnostics:
  • GIT_TRACE=1 GIT_CURL_VERBOSE=1 git push origin main

Minimal working example (local push)

Use a local bare remote to confirm your client is fine and isolate network/proxy issues.

# Create a demo repo
rm -rf /tmp/git-mwe && mkdir -p /tmp/git-mwe && cd /tmp/git-mwe
git init
printf "hello\n" > readme.txt
git add readme.txt
git commit -m "init"

# Create a local bare remote and push
mkdir -p /tmp/remote.git && cd /tmp/remote.git
git init --bare
cd /tmp/git-mwe
git remote add origin /tmp/remote.git
git branch -M main
git push -u origin main

If this local push works, your Git client and repo are fine. Failures against your real remote likely involve network, proxy, auth, or server policy.

Step-by-step troubleshooting

1. Verify the remote URL and connectivity

• git remote -v
• For HTTPS: git ls-remote <url>
• For SSH: ssh -T git@host (expect a greeting/permission message)

1. Enable trace logs to see the failure point

• GIT_TRACE=1 GIT_CURL_VERBOSE=1 git push origin main
• Look for: proxy in use, HTTP/2 frames, TLS errors, 413/50x, or abrupt FIN/RST

1. Disable HTTP/2 and Expect: 100-continue (HTTPS only)

• git config --global http.version HTTP/1.1
• git config --global http.expectContinue false

1. Fix proxy and SSL interception

• Unset unintended proxies:
  • git config --global --unset http.proxy
  • unset HTTPS_PROXY https_proxy HTTP_PROXY http_proxy
• If a corporate proxy is required, set it explicitly and ensure the proxy CA is trusted at the OS level.

1. Re-authenticate

• HTTPS: update or recreate your personal access token; ensure your credential helper stores it
  • git config --global credential.helper store|manager|osxkeychain|libsecret
• SSH: ensure the right key is offered and allowed
  • ssh -vT git@host to debug key selection

1. Handle large files properly

• Identify large blobs:

  git rev-list --objects --all \
  | git cat-file --batch-check='%(objecttype) %(objectname) %(objectsize) %(rest)' \
  | awk '$1=="blob"{printf "%-8.2f MB  %s\n", $3/1024/1024, $4}' \
  | sort -hr | head -20
  

• Track binaries with Git LFS (requires LFS installed):

  git lfs install
  git lfs track "*.bin" "*.zip" "*.iso"
  git add .gitattributes
  git commit -m "track large binaries via LFS"
  # Migrate existing history if needed (be cautious on shared repos)
  git lfs migrate import --include="*.bin,*.zip,*.iso"
  

1. Reduce pack size and memory use

• Repack locally before pushing:
  • git gc --aggressive --prune=now
• Limit resources if memory is tight:
  • git config --global pack.threads 1
  • git config --global pack.windowMemory 256m
  • git config --global pack.deltaCacheSize 256m

1. Push in smaller batches

• Split large changes across multiple commits/branches
• Push a single branch first: git push origin main
• Avoid pushing tags and all branches at once

1. Increase low-speed thresholds or avoid timeouts

• git config --global http.lowSpeedLimit 0
• git config --global http.lowSpeedTime 0

1. Check server-side causes (DevOps)

• Verify repository quotas, max upload size, and pre-receive hooks
• Ensure server has disk space and no reverse proxy/body-size limits
• Inspect server logs for TLS/proxy resets or hook failures

Common causes and fixes

Pitfalls to avoid

• Blindly increasing http.postBuffer: modern Git rarely needs this; it often masks real issues
• Disabling SSL verification: insecure; fix trust store instead
• Rewriting shared history during LFS migration without coordination
• Pushing everything (all branches/tags) at once when bandwidth is constrained
• Using --no-verify to bypass client hooks; it will not bypass server-side hooks

Performance notes

• Prefer SSH or HTTPS close to your infrastructure edge to minimize proxy hops
• Tune compression for your workload:
  • Faster push: git config --global core.compression 2
  • Smaller pack: core.compression 7–9 (slower CPU)
• For CI/CD runners, cache and reuse the Git object database between jobs to avoid re-packing
• Shallow clones reduce fetch size; shallow pushes are limited—unshallow before large pushes
• On servers, ensure adequate file descriptors, disk I/O, and adjust reverse proxy timeouts to exceed expected push duration

Tiny FAQ

Q: Why did increasing http.postBuffer seem to help once? A: It changed timing, not the root cause. Fix proxy/HTTP/2 issues or use LFS for large files.

Q: Is this error always client-side? A: No. It often indicates the server or an intermediary closed the connection. Check server logs and proxies.

Q: Does Git LFS fix all large push failures? A: It fixes binary transfer size issues, but proxies and server limits still need proper configuration.

Q: Can I switch protocols to work around the issue? A: Yes. If HTTPS fails, try SSH (and vice versa). This often bypasses a problematic proxy or TLS termination layer.