I'm curious if protobuf may have been upgraded to 2.5.0 on the Jenkins
slaves, ahead of committing the Hadoop code's dependency upgrade to 2.5.0.
We've started to see build failures due to cannot find symbol
com.google.protobuf.Parser. This is the earliest example I could find,
which happened 8/11 10:31 AM:
The Parser class does not exist in 2.4.1, but it does exist in 2.5.0, which
leads me to believe that the Jenkins machines were upgraded to start using
a 2.5.0 protoc binary.