The remote end hung up unexpectedly while git cloning

Quick solution:

With this kind of error, I usually start by raising the postBuffer size by:

git config --global http.postBuffer 524288000

(some comments below report having to double the value):

git config --global http.postBuffer 1048576000

(For npm publish, Martin Braun reports in the comments setting it to no more than 50 000 000 instead of the default 1 000 000)

###More information:

From the git config man page, http.postBuffer is about:

Maximum size in bytes of the buffer used by smart HTTP transports when POSTing data to the remote system.
For requests larger than this buffer size, HTTP/1.1 and Transfer-Encoding: chunked is used to avoid creating a massive pack file locally. Default is 1 MiB, which is sufficient for most requests.

Even for the clone, that can have an effect, and in this instance, the OP Joe reports:

[clone] works fine now

---

Note: if something went wrong on the server side, and if the server uses Git 2.5+ (Q2 2015), the error message might be more explicit.
See “Git cloning: remote end hung up unexpectedly, tried changing postBuffer but still failing“.

---

Kulai (in the comments) points out to this Atlassian Troubleshooting Git page, which adds:

Error code 56 indicates a curl receive the error of CURLE_RECV_ERROR which means there was some issue that prevented the data from being received during the cloning process.
Typically this is caused by a network setting, firewall, VPN client, or anti-virus that is terminating the connection before all data has been transferred.

It also mentions the following environment variable, order to help with the debugging process.

# Linux
export GIT_TRACE_PACKET=1
export GIT_TRACE=1
export GIT_CURL_VERBOSE=1

#Windows
set GIT_TRACE_PACKET=1
set GIT_TRACE=1
set GIT_CURL_VERBOSE=1

---

With Git 2.25.1 (Feb. 2020), you know more about this http.postBuffer “solution”.

See commit 7a2dc95, commit 1b13e90 (22 Jan 2020) by brian m. carlson (bk2204).
^{(Merged by Junio C Hamano — gitster — in commit 53a8329, 30 Jan 2020)}
(Git Mailing list discussion)

docs: mention when increasing http.postBuffer is valuable

^{Signed-off-by: brian m. carlson}

Users in a wide variety of situations find themselves with HTTP push problems.

Oftentimes these issues are due to antivirus software, filtering proxies, or other man-in-the-middle situations; other times, they are due to simple unreliability of the network.

However, a common solution to HTTP push problems found online is to increase http.postBuffer.

This works for none of the aforementioned situations and is only useful in a small, highly restricted number of cases: essentially, when the connection does not properly support HTTP/1.1.

Document when raising this value is appropriate and what it actually does, and discourage people from using it as a general solution for push problems, since it is not effective there.

So the documentation for git config http.postBuffer now includes:

http.postBuffer

Maximum size in bytes of the buffer used by smart HTTP transports when POSTing data to the remote system.
For requests larger than this buffer size, HTTP/1.1 and Transfer-Encoding: chunked is used to avoid creating a massive pack file locally.
Default is 1 MiB, which issufficient for most requests.

Note that raising this limit is only effective for disabling chunked transfer encoding and therefore should be used only where the remote server or a proxy only supports HTTP/1.0 or is noncompliant with the HTTP standard.
Raising this is not, in general, an effective solution for most push problems, but can increase memory consumption significantly since the entire buffer is allocated even for small pushes.