I'm not sure quite how to report bugs with BuildTools or how it works, so please tell me if you need anymore information. This error occurs when running BuildTools.jar #17 (https://hub.spigotmc.org/jenkins/job/BuildTools/17/). I have ran it many times before and never had an error. I tried deleting all of the files and building from just the jar, but it results in the same thing. This happened about 10 minutes ago. I'm not sure if this is something I should worry about, or if it is harmless.

Results :

Tests in error:
testKnownAttributes(org.bukkit.craftbukkit.inventory.ItemFactoryTest): net/md_5/bungee/api/chat/BaseComponent : Unsupported major.minor version 51.0

Tests run: 4887, Failures: 0, Errors: 1, Skipped: 0

[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO]
[INFO] Spigot-API ......................................... SUCCESS [ 7.347 s]
[INFO] Spigot-Parent ...................................... SUCCESS [ 0.100 s]
[INFO] Spigot ............................................. FAILURE [ 10.773 s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 18.351 s
[INFO] Finished at: 2014-12-15T18:58:27-08:00
[INFO] Final Memory: 49M/870M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.11:test (default-test) on project spigot: There are test failures.
[ERROR]
[ERROR] Please refer to /backup/minecraft_v2/spigot_cooking/1.8+/Spigot/Spigot-Server/target/surefire-reports for the individual test results.
[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/MojoFailureException
[ERROR]
[ERROR] After correcting the problems, you can resume the build with the command
[ERROR] mvn <goals> -rf :spigot
Error compiling Spigot, are you running this jar via msysgit?
java.lang.RuntimeException: Error running command, return status !=0: [sh, /backup/minecraft_v2/spigot_cooking/1.8+/apache-maven-3.2.3/bin/mvn, clean, install]
at org.spigotmc.builder.Builder.runProcess(Builder.java:393)
at org.spigotmc.builder.Builder.main(Builder.java:314)
spigot.jar does not exists in the minecraft_v2 directory.
Cannot copy new spigot build to the minecraft_v2 directory.