Environment

gitbucket version: 3.6
local git version: 2.4.3

Problem

gitbucketにpushするときに以下のエラーが発生した

$ git push
Counting objects: 42, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (41/41), done.
Writing objects: 100% (42/42), 28.99 KiB | 0 bytes/s, done.
Total 42 (delta 24), reused 0 (delta 0)
remote: error: Internal server error
fatal: The remote end hung up unexpectedly
fatal: The remote end hung up unexpectedly
error: failed to push some refs to 'http://xxx.git'

gitbucketのログには以下のようなエラーが表示されていた

# /var/log/upstart/gitbucket.log

2015-11-09 15:57:38.451:WARN:/:Internal error during receive-pack
org.eclipse.jgit.errors.PackProtocolException: error: invalid protocol: wanted 'old new ref'
	at org.eclipse.jgit.transport.BaseReceivePack.recvCommands(BaseReceivePack.java:935)
	at org.eclipse.jgit.transport.ReceivePack.service(ReceivePack.java:184)
	at org.eclipse.jgit.transport.ReceivePack.receive(ReceivePack.java:160)
	at org.eclipse.jgit.http.server.ReceivePackServlet.doPost(ReceivePackServlet.java:187)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:755)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)

Solution

参考: http://stackoverflow.com/questions/21557004/protocol-error-expected-old-new-ref-got-shallow-deeb

unshallowした後にpushすると成功した

$ git fetch --unshallow
$ git push