When executing the build on the slave, sometimes (it seems to happen when the build duration is considerable, like building for the webplayer), the plugin fails with:

... [NORMAL BUILD OUTOUT] ...

LZMA 4.43 Copyright (c) 1999-2006 Igor Pavlov 2006-06-04
Failure on remote
java.io.IOException: Pipe broken
at java.io.PipedInputStream.read(Unknown Source)
at java.io.PipedInputStream.read(Unknown Source)
at java.io.InputStream.read(Unknown Source)
at org.jenkinsci.plugins.unity3d.io.StreamCopyThread.run(StreamCopyThread.java:64)
... [Jenkins internal stack trace] ...

It fails after the LZMA compression ends (the process lasts several minutes).