Checkout from git via SSH fails with NoClassDefFoundError

2016-01-21 04:18:36,233 INFO [10-BAM::PlanExec:pool-17-thread-2] [DefaultErrorHandler] Recording an error: Unable to detect changes : TP-TP : com.atlassian.bamboo.plugins.git.GitCommandException: command /usr/local/bin/git ls-remote ssh://1e9360ab-6bd0-48bf-95b5-b7f9f2accb1d@127.0.0.1:47121/foo/bar.git failed with code 128. Working directory was [.]., stderr:
Authenticating remote session failed
stdout:
[Warning: Permanently added '[127.0.0.1]:47121' (RSA) to the list of known hosts., BAMBOO-SSH-PROXY: [While connecting to [git@bitbucket.org/104.192.143.3:22]: Authenticating remote session failed: Session is closed], fatal: Could not read from remote repository., , Please make sure you have the correct access rights, and the repository exists.]
2016-01-21 04:18:48,140 INFO [13-BAM::Default Agent::Agent:pool-28-thread-1] [BuildAgentControllerImpl] Agent 131073 checking build queue for executables...
2016-01-21 04:18:49,353 WARN [PluginSchedulerTask-com.atlassian.bamboo.analytics.basedata.collector.CollectionJob:job] [AuthorizationLoggerListener] Credentials not found: org.acegisecurity.AuthenticationCredentialsNotFoundException: An Authentication object was not found in the SecurityContext; secure object: ReflectiveMethodInvocation: public abstract java.util.List com.atlassian.bamboo.plan.PlanManager.getAllPlans(java.lang.Class); target is of class [com.atlassian.bamboo.plan.PlanManagerImpl]; configuration attributes: [ROLE_USER, ROLE_ANONYMOUS, AFTER_ACL_COLLECTION_READ]
2016-01-21 04:21:32,799 WARN [sshd-SshClient[4772488e]-nio2-thread-2] [ClientSessionImpl] Exception caught
java.lang.NoClassDefFoundError: com/jcraft/jzlib/ZStream
	at org.apache.sshd.common.compression.CompressionZlib.init(CompressionZlib.java:67)
	at org.apache.sshd.common.session.AbstractSession.receiveNewKeys(AbstractSession.java:1000)
	at org.apache.sshd.common.session.AbstractSession.doHandleMessage(AbstractSession.java:366)
	at org.apache.sshd.common.session.AbstractSession.handleMessage(AbstractSession.java:295)
	at org.apache.sshd.client.session.ClientSessionImpl.handleMessage(ClientSessionImpl.java:256)
	at org.apache.sshd.common.session.AbstractSession.decode(AbstractSession.java:731)
	at org.apache.sshd.common.session.AbstractSession.messageReceived(AbstractSession.java:277)
	at org.apache.sshd.common.AbstractSessionIoHandler.messageReceived(AbstractSessionIoHandler.java:54)
	at org.apache.sshd.common.io.nio2.Nio2Session$1.onCompleted(Nio2Session.java:187)
	at org.apache.sshd.common.io.nio2.Nio2Session$1.onCompleted(Nio2Session.java:173)
	at org.apache.sshd.common.io.nio2.Nio2CompletionHandler$1.run(Nio2CompletionHandler.java:32)
	at java.security.AccessController.doPrivileged(Native Method)
	at org.apache.sshd.common.io.nio2.Nio2CompletionHandler.completed(Nio2CompletionHandler.java:30)
	at sun.nio.ch.Invoker.invokeUnchecked(Invoker.java:126)
	at sun.nio.ch.Invoker$2.run(Invoker.java:218)
	at sun.nio.ch.AsynchronousChannelGroupImpl$1.run(AsynchronousChannelGroupImpl.java:112)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)