Unable to compile after Pants bootstrap

[olafurpg]

I was able to run the bootstrap from the bootstrap branch

git checkout topic/hydra-boostrapper-jar
./pants publish.jar --no-prompt --no-dryrun --named-snapshot=0.0.13-SNAP5 --local=~/.m2/repository src/scala/org/pantsbuild/zinc/bootstrapper:bootstrapper
# OK

Then I checked out topic/hydra-support and got an error "failed: No bootstrap callback registered for hydra in zinc" when running ./pants compile

./pants compile examples/src/scala/org/pantsbuild/example/hello::

16:29:57 00:00 [main]
               (To run a reporting server: ./pants server)
16:29:57 00:00   [setup]
16:29:58 00:01     [parse]
               Executing tasks in goals: bootstrap -> imports -> unpack-wheels -> unpack-jars -> deferred-sources -> gen -> native-compile -> jvm-platform-validate -> resolve -> resources -> compile
16:29:58 00:01   [bootstrap]
16:29:58 00:01     [substitute-aliased-targets]
16:29:58 00:01     [jar-dependency-management]
16:29:58 00:01     [bootstrap-jvm-tools]
16:29:58 00:01     [provide-tools-jar]
16:29:58 00:01   [imports]
16:29:58 00:01     [ivy-imports]
16:29:58 00:01   [unpack-wheels]
16:29:58 00:01     [unpack-wheels]
16:29:58 00:01   [unpack-jars]
16:29:58 00:01     [unpack-jars]
16:29:58 00:01   [deferred-sources]
16:29:58 00:01     [deferred-sources]
16:29:58 00:01   [gen]
16:29:58 00:01     [antlr-java]
16:29:58 00:01     [antlr-py]
16:29:58 00:01     [jaxb]
16:29:58 00:01     [protoc]
16:29:58 00:01     [ragel]
16:29:58 00:01     [thrift-java]
16:29:58 00:01     [thrift-py]
16:29:58 00:01     [py-thrift-namespace-clash-check]
16:29:58 00:01     [grpcio-prep]
16:29:58 00:01     [grpcio-run]
16:29:58 00:01     [wire]
16:29:58 00:01     [avro-java]
16:29:58 00:01     [go-thrift]
16:29:58 00:01     [go-protobuf]
16:29:58 00:01     [jax-ws]
16:29:58 00:01     [scrooge]
16:29:58 00:01     [thrifty]
16:29:58 00:01   [native-compile]
16:29:58 00:01     [conan-prep]
16:29:58 00:01     [conan-fetch]
16:29:58 00:01     [c-for-ctypes]
16:29:58 00:01     [cpp-for-ctypes]
16:29:58 00:01   [jvm-platform-validate]
16:29:58 00:01     [jvm-platform-validate]
16:29:58 00:01   [resolve]
16:29:58 00:01     [ivy]
16:29:59 00:02     [coursier]
16:29:59 00:02     [go]
16:29:59 00:02     [scala-js-compile]
16:29:59 00:02     [scala-js-link]
16:29:59 00:02     [node]
16:29:59 00:02   [resources]
16:29:59 00:02     [prepare]
16:29:59 00:02     [services]
16:29:59 00:02   [compile]
16:29:59 00:02     [node]
16:29:59 00:02     [compile-jvm-prep-command]
16:29:59 00:02       [jvm_prep_command]
16:29:59 00:02     [compile-prep-command]
16:29:59 00:02     [compile]
16:29:59 00:02     [rsc]
                   Invalidated 3 targets.
16:29:59 00:02       [isolation-mixed-pool-bootstrap]
                   [1/3] Compiling 1 mixed source in 1 target (examples/src/java/org/pantsbuild/example/hello/greet:greet).
16:29:59 00:02       [compile]
                     
                   zinc[zinc-java](examples/src/java/org/pantsbuild/example/hello/greet:greet) failed: No bootstrap callback registered for hydra in zinc in 0.05608081817626953
                   Traceback:
                     File "/Users/lgeirsson/dev/triplequote/pants/src/python/pants/backend/jvm/tasks/jvm_compile/execution_graph.py", line 287, in worker
                       work()
                   
                     File "/Users/lgeirsson/dev/triplequote/pants/src/python/pants/backend/jvm/tasks/jvm_compile/execution_graph.py", line 47, in __call__
                       self.fn()
                   
                     File "/Users/lgeirsson/dev/triplequote/pants/src/python/pants/backend/jvm/tasks/jvm_compile/jvm_compile.py", line 993, in _default_work_for_vts
                       counter)
                   
                     File "/Users/lgeirsson/dev/triplequote/pants/src/python/pants/backend/jvm/tasks/jvm_compile/jvm_compile.py", line 593, in _compile_vts
                       self._get_plugin_map('scalac', ScalaPlatform.global_instance(), ctx.target),
                   
                     File "/Users/lgeirsson/dev/triplequote/pants/src/python/pants/backend/jvm/tasks/jvm_compile/zinc/zinc_compile.py", line 318, in compile
                       compiler_bridge_classpath_entry = self._zinc.compile_compiler_bridge(self.context)
                   
                     File "/Users/lgeirsson/dev/triplequote/pants/src/python/pants/util/memo.py", line 115, in memoize
                       result = func(*args, **kwargs)
                   
                     File "/Users/lgeirsson/dev/triplequote/pants/src/python/pants/backend/jvm/subsystems/zinc.py", line 392, in compile_compiler_bridge
                       return self._compile_compiler_bridge(context)
                   
                     File "/Users/lgeirsson/dev/triplequote/pants/src/python/pants/backend/jvm/subsystems/zinc.py", line 419, in _compile_compiler_bridge
                       res = self._run_bootstrapper(bridge_jar, context)
                   
                     File "/Users/lgeirsson/dev/triplequote/pants/src/python/pants/backend/jvm/subsystems/zinc.py", line 357, in _run_bootstrapper
                       extra_jars = map(lambda cp_entry: cp_entry.path, self._compiler_extra_jars)
                   
                     File "/Users/lgeirsson/dev/triplequote/pants/src/python/pants/util/memo.py", line 115, in memoize
                       result = func(*args, **kwargs)
                   
                     File "/Users/lgeirsson/dev/triplequote/pants/src/python/pants/backend/jvm/subsystems/zinc.py", line 284, in _compiler_extra_jars
                       return self._zinc_factory._compiler_extra_jars(self._products)
                   
                     File "/Users/lgeirsson/dev/triplequote/pants/src/python/pants/backend/jvm/subsystems/zinc.py", line 174, in _compiler_extra_jars
                       return cls.tool_jar_entries_from_products(products, 'hydra', cls.options_scope)
                   
                     File "/Users/lgeirsson/dev/triplequote/pants/src/python/pants/backend/jvm/subsystems/jvm_tool_mixin.py", line 215, in tool_jar_entries_from_products
                       classpath = cls.tool_classpath_entries_from_products(products, key, scope)
                   
                     File "/Users/lgeirsson/dev/triplequote/pants/src/python/pants/backend/jvm/subsystems/jvm_tool_mixin.py", line 241, in tool_classpath_entries_from_products
                       .format(key=key, scope=scope))
                   
               Waiting for background workers to finish.
16:29:59 00:02   [complete]
               FAILURE.pants.d/bootstrap/bootstrap-jvm-tools/tool_cache/shaded_jars/org.pantsbuild.zinc.bootstrapper.Main-550b4a6ea70c277a54151bb9d725b110c323cb07-ShadedToolFingerprintStrategy_a504e3b87802.jar
candidates scala-compiler
[ArtifactClasspathEntry(path='/Users/lgeirsson/dev/triplequote/pants/.pants.d/bootstrap/bootstrap-jvm-tools/a0ebe8e0b001/ivy/jars/org.scala-lang/scala-compiler/jars/scala-compiler-2.12.8.jar', coordinate=M2Coordinate(org='org.scala-lang', name='scala-compiler', rev='2.12.8', classifier=None, ext='jar'), cache_path='/Users/lgeirsson/.ivy2/pants/org.scala-lang/scala-compiler/jars/scala-compiler-2.12.8.jar', directory_digest=Digest(fingerprint='d85ac1982d8a91b00bde1b1a1f668d0ce0f9cf7ff124582ed8f9a41eb7ddd0e8', serialized_bytes_length=82))]
candidates scala-library
[ArtifactClasspathEntry(path='/Users/lgeirsson/dev/triplequote/pants/.pants.d/bootstrap/bootstrap-jvm-tools/a0ebe8e0b001/ivy/jars/org.scala-lang/scala-library/jars/scala-library-2.12.8.jar', coordinate=M2Coordinate(org='org.scala-lang', name='scala-library', rev='2.12.8', classifier=None, ext='jar'), cache_path='/Users/lgeirsson/.ivy2/pants/org.scala-lang/scala-library/jars/scala-library-2.12.8.jar', directory_digest=Digest(fingerprint='13e47e7c554f2d0843556a62e236e5527cef4eca5e791c55fbf881c282e51e8d', serialized_bytes_length=82))]
candidates scala-reflect
[ArtifactClasspathEntry(path='/Users/lgeirsson/dev/triplequote/pants/.pants.d/bootstrap/bootstrap-jvm-tools/a0ebe8e0b001/ivy/jars/org.scala-lang/scala-reflect/jars/scala-reflect-2.12.8.jar', coordinate=M2Coordinate(org='org.scala-lang', name='scala-reflect', rev='2.12.8', classifier=None, ext='jar'), cache_path='/Users/lgeirsson/.ivy2/pants/org.scala-lang/scala-reflect/jars/scala-reflect-2.12.8.jar', directory_digest=Digest(fingerprint='01d8b940bb35d0050594a12de8a0e3d4d34e276ae9d2c09fd03b13bce9d0b2f5', serialized_bytes_length=82))]

FAILURE: Compilation failure: Failed jobs: zinc[zinc-java](examples/src/java/org/pantsbuild/example/hello/greet:greet)

Any idea what I might be doing wrong?