Plugins installed: [default]

JVM version : 1.8.0_102

OS version : Windows 7

Description of the problem including expected versus actual behavior:

Issue is Windows specific. Gradle tasks throws out error "unknown Property "HADOOP_HOME" if HADOOP_HOME is set in the system.

Issue is due to referencing unknown property HADOOP_HOME in the exception statement

Steps to reproduce:

1. Set HADOOP_HOME
2. Make sure that any of the files winUtils.exe, hdfs.dll or hadoop.dll is not present in HADOOP_HOME\bin
3. Run any of the gradle tasks
4. Observe that you get error "unknown property HADOOP_HOME in plugins\repository-hdfs\build.gradle #line_number:40

Provide logs (if relevant):

FAILURE: Build failed with an exception.

• Where:
  Build file 'C:......\elasticsearch\plugins\repository-hdfs\build.gradle' line: 140

• What went wrong:
  A problem occurred evaluating project ':plugins:repository-hdfs'.

Could not get unknown property 'HADOOP_HOME' for project ':plugins:repository-hdfs' of type org.gradle.api.Project.