VS2015 Build failure with protoc

[Scott Inglis <ms...@gmail.com>]

I am getting the following build failure with my change -- which upgrades
the protobuf library to 2.1.0. Running the same command on my machine does
not repro the error locally. I am using protoc exe version 2.5.0.

What version of protoc is used on the AppVeryor machines?

Here is the error:

VS2015 ran but has an error ant exception - which may look valid:
24>Build:
[ERROR] Failed to execute goal
org.apache.maven.plugins:maven-antrun-plugin:1.7:run (generate-sources) on
project reef-common: An Ant BuildException has occured: 2.5.0 expected, but
protoc version was:
[ERROR] around Ant part ...... @ 7:77 in
C:\projects\reef\lang\java\reef-common\target\antrun\build-main.xml
[ERROR] -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e
switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions,
please read the following articles:
[ERROR] [Help 1]
http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
[ERROR]
[ERROR] After correcting the problems, you can resume the build with the
command
[ERROR] mvn -rf :reef-common