The first thing that protoc mojo does from add-maven plugins is to use the Java class java.lang.Process to try and execute the following command:
protoc --version
This is mainly done to verify that the protocol protocol compiler (protoc) version on your system matches the protobuf JAR version.
There are 4 results for this:
- he could not find the
protoc command to execute (gets the output value 127) - it does not get the output value 127, but also does not get the return value of the version
- the version is returned, but does not match the protobuf jar version
- the version is returned and it matches the protobuf jar version
You are experiencing a second problem.
If you try to run protoc --version from the command line, will this work?
As they claim on their website, if you have several versions of protoc on your system, you can set the HADOOP_PROTOC_PATH environment variable in the assembly shell to indicate the one you want to use to build Hadoop. If you do not define this environment variable, protoc looked up in PATH . Is this available on your PATH ?
If you have not installed the Buffer protocol compiler, you can download it from the following location: https://developers.google.com/protocol-buffers/docs/downloads