We have two build agents/modes set up on our Hudson instance. When a build that is using the current
SCP publisher plugin attempts to SFTP files and fails, it causes the next build on that agent/node to
hang/freeze - right before it does the SVN update.

The failed SCP publishing stack trace typically looks like:

ERROR: Failed to upload files
4: invalid type=0
at com.jcraft.jsch.ChannelSftp.put(Unknown Source)
at com.jcraft.jsch.ChannelSftp.put(Unknown Source)
at be.certipost.hudson.plugin.SCPSite.upload(SCPSite.java:201)
at be.certipost.hudson.plugin.SCPRepositoryPublisher.perform(SCPRepositoryPublisher.java:125)
at hudson.model.AbstractBuild$AbstractRunner.performAllBuildStep(AbstractBuild.java:322)
at hudson.model.AbstractBuild$AbstractRunner.performAllBuildStep(AbstractBuild.java:310)
at hudson.model.Build$RunnerImpl.post2(Build.java:126)
at hudson.model.AbstractBuild$AbstractRunner.post(AbstractBuild.java:295)
at hudson.model.Run.run(Run.java:852)
at hudson.model.Build.run(Build.java:88)
at hudson.model.ResourceController.execute(ResourceController.java:70)
at hudson.model.Executor.run(Executor.java:90)
finished: UNSTABLE

Disabling the SCP plugin fixed our builds from hanging.

We're using Hudson 1.270 and SCP plugin version 1.5.2.