It depends on the version of protoc.
Protocol Buffer Compiler is a native application and is distributed as a binary executable file.
Previously, it was not distributed via Maven repository, but that policy has recently changed.
Starting with versions 2.6.1 and 3.0.0-alpha-2, binary executables
for all major operating systems are available as artifacts in Maven central, and these artifacts
can be referenced in plugin configuration.
For any prior versions the application developer will need to configure protoc executable location
for the plugin, either explicitly with protocExecutable plugin configuration parameter,
or, preferably, by using protobuf toolchain.
There is a limited support in the plugin for integration with M2E 1.5 and later.
Versions of M2E prior to 1.5 will fail to work with the plugin because of a
class loading bug.
Also, if using os-maven-plugin to help resolve binary artifacts,
please make sure that you have read
these important notes.
