*Enviroment: *
Ubuntu 14.04.2 LTS
Jenkins 2.7 running under Nginx
ssh-agent 1.10

Logs
```Started by user Ezequiel Golub
Changing BUILD_ID variable (job build time) with the date pattern yyyy-MM-dd_HH-mm-ss.
Changing BUILD_ID variable (job build time) with the date pattern yyyy-MM-dd_HH-mm-ss.
Published SNS notification: subject=Build STARTED: build-environment #6950 topic=arn:aws:sns:us-east-1:139903529341:jenkins-production-infrastructure
[EnvInject] - Loading node environment variables.
Changing BUILD_ID variable (job build time) with the date pattern yyyy-MM-dd_HH-mm-ss.
Building on masterChanging BUILD_ID variable (job build time) with the date pattern yyyy-MM-dd_HH-mm-ss.
in workspace /home/deploy/environments
[ssh-agent] Looking for ssh-agent implementation...
[ssh-agent] Java/JNR ssh-agent
[ssh-agent] FATAL: Could not find a suitable ssh-agent provider
[ssh-agent] Diagnostic report
[ssh-agent] * Java/JNR ssh-agent
[ssh-agent] java.io.IOException: No such file or directory
[ssh-agent] at java.io.UnixFileSystem.createFileExclusively(Native Method)
[ssh-agent] at java.io.File.createNewFile(File.java:1006)
[ssh-agent] at java.io.File.createTempFile(File.java:1989)
[ssh-agent] at com.cloudbees.jenkins.plugins.sshagent.jna.AgentServer.createLocalSocketAddress(AgentServer.java:142)
[ssh-agent] at com.cloudbees.jenkins.plugins.sshagent.jna.AgentServer.start(AgentServer.java:78)
[ssh-agent] at com.cloudbees.jenkins.plugins.sshagent.jna.JNRRemoteAgent.<init>(JNRRemoteAgent.java:70)
[ssh-agent] at com.cloudbees.jenkins.plugins.sshagent.jna.JNRRemoteAgentStarter.call(JNRRemoteAgentStarter.java:68)
[ssh-agent] at com.cloudbees.jenkins.plugins.sshagent.jna.JNRRemoteAgentStarter.call(JNRRemoteAgentStarter.java:39)
[ssh-agent] at hudson.remoting.LocalChannel.call(LocalChannel.java:45)
[ssh-agent] at com.cloudbees.jenkins.plugins.sshagent.jna.JNRRemoteAgentFactory.start(JNRRemoteAgentFactory.java:62)
[ssh-agent] at com.cloudbees.jenkins.plugins.sshagent.SSHAgentBuildWrapper$SSHAgentEnvironment.<init>(SSHAgentBuildWrapper.java:360)
[ssh-agent] at com.cloudbees.jenkins.plugins.sshagent.SSHAgentBuildWrapper.createSSHAgentEnvironment(SSHAgentBuildWrapper.java:248)
[ssh-agent] at com.cloudbees.jenkins.plugins.sshagent.SSHAgentBuildWrapper.preCheckout(SSHAgentBuildWrapper.java:225)
[ssh-agent] at jenkins.scm.SCMCheckoutStrategy.preCheckout(SCMCheckoutStrategy.java:76)
[ssh-agent] at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:528)
[ssh-agent] at hudson.model.Run.execute(Run.java:1738)
[ssh-agent] at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)
[ssh-agent] at hudson.model.ResourceController.execute(ResourceController.java:98)
[ssh-agent] at hudson.model.Executor.run(Executor.java:410)
FATAL: [ssh-agent] Unable to start agent
hudson.util.IOException2: [ssh-agent] Unable to start agent
at com.cloudbees.jenkins.plugins.sshagent.SSHAgentBuildWrapper.createSSHAgentEnvironment(SSHAgentBuildWrapper.java:255)
at com.cloudbees.jenkins.plugins.sshagent.SSHAgentBuildWrapper.preCheckout(SSHAgentBuildWrapper.java:225)
at jenkins.scm.SCMCheckoutStrategy.preCheckout(SCMCheckoutStrategy.java:76)
at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:528)
at hudson.model.Run.execute(Run.java:1738)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)
at hudson.model.ResourceController.execute(ResourceController.java:98)
at hudson.model.Executor.run(Executor.java:410)
Caused by: java.lang.RuntimeException: [ssh-agent] Could not find a suitable ssh-agent provider.
at com.cloudbees.jenkins.plugins.sshagent.SSHAgentBuildWrapper$SSHAgentEnvironment.<init>(SSHAgentBuildWrapper.java:378)
at com.cloudbees.jenkins.plugins.sshagent.SSHAgentBuildWrapper.createSSHAgentEnvironment(SSHAgentBuildWrapper.java:248)
... 7 more
Changing BUILD_ID variable (job build time) with the date pattern yyyy-MM-dd_HH-mm-ss.
Changing BUILD_ID variable (job build time) with the date pattern yyyy-MM-dd_HH-mm-ss.
Published SNS notification: subject=Build FAILURE: build-environment #6950 topic=arn:aws:sns:us-east-1:139903529341:jenkins-production-infrastructure
Changing BUILD_ID variable (job build time) with the date pattern yyyy-MM-dd_HH-mm-ss.
Warning: you have no plugins providing access control for builds, so falling back to legacy behavior of permitting any downstream builds to be triggered
Finished: FAILURE```

Analysis
My best guess is that it's trying to create a file in `AgentServer.java:142`, but it's generating and invalid path. I tried chmod 777 on it's workspace, just to be sure, and it didn't help.
We were upgrading from ssh-agent 1.5 to 1.10, didn't work, ended up downgrading to 1.9 to avoid this issue.
I'm not a java guy, but i'll be happy to provide any other information needed to fix this.