InternalProvisionException.errorInUserCode discards important context about user errors

[michkot]

There is a special case in InternalProvisionException.errorInUserCode

guice/core/src/com/google/inject/internal/InternalProvisionException.java

Lines 91 to 102 in e960b66

	public static InternalProvisionException errorInUserCode(
	ErrorId errorId, Throwable cause, String messageFormat, Object... arguments) {
	Collection<Message> messages = Errors.getMessagesFromThrowable(cause);
	if (!messages.isEmpty()) {
	// TODO(lukes): it seems like we are dropping some valuable context here..
	// consider eliminating this special case
	return new InternalProvisionException(messages);
	} else {
	return new InternalProvisionException(
	Messages.create(errorId, cause, messageFormat, arguments));
	}
	}

which has been pre-flagged as TODO by the author of the function (see git blame https://github.com/google/guice/blame/e960b66d3d5931b9cb1aebd49e452e2c489a921e/core/src/com/google/inject/internal/InternalProvisionException.java#L95) as a potential problem, and I was just hit by this - it indeed discard important context!

What was happening is there was:

• guice's provider of ClassA .get being called,
• instantiating the actual custom provider ClassAProvider, then calling its .get
• doing a lot of work, part of it (4 stack frame bellow) is happening in ClassX, doing injector.getInstance for ClassB -> this fails with ConfigurationError
• the ConfigurationError (with the relevant stacktrace) is discarded in .errorInUserCode, only its message is kept.

What did I observe?
A ProvisionException that talks about failing to provision ClassB, while provisioning ClassA via ClassAProvider. If you look into ClassAProvider construtor, you don't see any ties to ClassB. It does not mention that code of ClassX in anyway in the text or stacktrace.

You have to start debugging ClassAProvider / Guice itself to find out where is the nested Guice error happening / being discarded.

[Malaydewangan09]

hey! @cpovirk Is this issue still there ?
Do let me know to resolve this .
Thanks!