Here's what I believe to be the relevant error message:
Caused by: java.io.IOException: Cannot run program "/usr/bin/git" (in directory "/var/lib/hudson/jobs/Goals/workspace"): java.io.IOException: error=12, Cannot allocate memory
at java.lang.ProcessBuilder.start(ProcessBuilder.java:474)
at hudson.Proc$LocalProc.<init>(Proc.java:192)
at hudson.Proc$LocalProc.<init>(Proc.java:164)
at hudson.Launcher$LocalLauncher.launch(Launcher.java:638)
at hudson.Launcher$ProcStarter.start(Launcher.java:273)
at hudson.Launcher$ProcStarter.join(Launcher.java:280)
at hudson.plugins.git.GitAPI.launchCommandIn(GitAPI.java:319)
... 15 more
Caused by: java.io.IOException: java.io.IOException: error=12, Cannot allocate memory
at java.lang.UNIXProcess.<init>(UNIXProcess.java:164)
at java.lang.ProcessImpl.start(ProcessImpl.java:81)
at java.lang.ProcessBuilder.start(ProcessBuilder.java:467)
... 21 more
You can also see the full output from Hudson here: http://hudson.pastebin.com/KLSNrY1D
Any ideas? How can I stop this from happening? I'm not a Java dev, so I don't know much about what's going on here. I have to restart Hudson entirely to fix the issue, but clearly this is not the best answer.