### Viewing `env_logger` output in failing tests.
To see the full output of logging, invoke `cargo test` this way:
`RUST_LOG=trace cargo test -- --nocapture`
Notes:
- Using `RUST_LOG=trace` to set the log level to `trace`, giving maximal output for failing tests.
- Using `-- --nocapture` to suppress the default test behavior of capturing and omitting `stdout`
#### Background
Usually, logs go to standard error, not standard output, and they are
used to monitor normal operations of a CLI tool or server program.
However behavior is misaligned with the setup of `cargo test --
--nocapture`, which only looks at `stdout`, and ignores `stderr`.
To fix this undesirable default, we use this package:
https://github.com/d-e-s-o/test-log
It redirects logging to `stdout`, which is what we want for tests run with `cargo test`.
We place `use test_log::test;` in in the tests that use it.