Panic without good error message in prost-build when message not in graph #1282
Description
Just like #932, prost-build panics without a good error message when a message is somehow not in the message graph:
prost/prost-build/src/context.rs
Lines 172 to 180 in 1e93f56
Encountered when trying to compile potentially well-known protos within google/rpc/*.proto:
thread 'main' panicked at /Users/kris/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/prost-build-0.13.5/src/context.rs:181:14:
called `Option::unwrap()` on a `None` value
It would be nice rich errors were provided, potentially something simple like anyhow::{Context, Error}, instead of panicing without specifying which message name the build had a problem with.