GraphvizGrapher does not support optional bindings. Fails with error even though Guice application works

Using the GraphvizGrapher to graph a working application. However, the grapher gives the following exception when it cannot find a binding for an optional binding.

1) testMakeGrowGraph(com.google.corp.talent.common.guicegrapher.GuiceGrapherTest)com.google.inject.ConfigurationException: Guice configuration errors:

1) No implementation for com.google.template.soy.msgs.SoyMsgPlugin was bound.
while locating com.google.template.soy.msgs.SoyMsgPlugin
for parameter 0 at com.google.template.soy.msgs.SoyMsgBundleHandler.(SoyMsgBundleHandler.java:108)
while locating com.google.inject.Provider

1 error
at com.google.inject.internal.InjectorImpl.getBinding(InjectorImpl.java:160)
at com.google.inject.internal.InjectorImpl.getBinding(InjectorImpl.java:68)
at com.google.inject.grapher.AbstractInjectorGrapher.getBindings(AbstractInjectorGrapher.java:220)
at com.google.inject.grapher.AbstractInjectorGrapher.graph(AbstractInjectorGrapher.java:108)
at com.google.inject.grapher.AbstractInjectorGrapher.graph(AbstractInjectorGrapher.java:102)
at com.google.corp.talent.common.guicegrapher.GuiceGrapher.getStringGraph(GuiceGrapher.java:87)