Looking at the source code https://docs.rs/crate/failure/0.1.3/source/src/backtrace/int..., "failure" uses https://docs.rs/backtrace/0.3.9/backtrace/struct.Backtrace.h... which is the callstack at a single point, not a trace of how an error was propagated.
Looking at the source code https://docs.rs/crate/failure/0.1.3/source/src/backtrace/int..., "failure" uses https://docs.rs/backtrace/0.3.9/backtrace/struct.Backtrace.h... which is the callstack at a single point, not a trace of how an error was propagated.