This switches to using the tracing crate instead of log. Tracing
provides a lot of nice features which we can take advantage of moving
forward.
This also adjusts the output fairly significantly. This includes:
- Switched the environment variable from RUST_LOG to MDBOOK_LOG.
- Dropped the timestamp. I experimented with various different time
displays, but ultimately decided to omit it for now. I don't think
I've ever found it to be useful, and it takes up a very significant
amount of space. It could potentially be useful for basic profiling,
but I think there are other, better mechanisms for that. We could
consider leveraging tracing itself for doing some basic profiling
(like using something like tracing-chrome).
- Dropped the target unless MDBOOK_LOG is set. The target tends to be
pretty noisy, and doesn't really convey much information unless you
are debugging or otherwise trying to adjust the log output.
- Added color.
- Slightly reworked the way the error cause trace is displayed.
- Slightly changed the way html5ever filtering is done, as well as add
handlebars to the list since they both are very noisy. You can
override this now by explicitly listing them as targets.
I still expect that mdbook will eventually change how it displays things
to the console, possibly switching away from tracing and printing things
itself. However, that is a larger project for the future.
This changes the serialization so that `book.src` is not serialized if
it is the default. This removes the somewhat pointless `src = "src"`
which shows up in the default `mdbook init` output. Deserialization
should still default to `"src"`.
This changes it so that it is an error if there is ever an unknown
configuration field. This is intended to help avoid things like typos,
or using an outdated version of mdbook. Although it is possible that new
fields could potentially safely be ignored, setting up a warning system
is a bit more of a hassle. I don't think mdbook needs to have the same
kind of multi-version support as something like cargo does. However, if
this ends up being too much of a pain point, we can try to add a warning
system instead.
There are a variety of changes here:
- The top-level config namespace is now closed so that it only accepts
the keys defined in `Config`.
- All config tables now reject unknown fields.
- Added `Config::outputs` and `Config::preprocessors` for convenience
to access the entire `output` and `preprocessor` tables.
- Moved the unit-tests that were setting environment variables to the
testsuite where it launches a process instead.
Closes https://github.com/rust-lang/mdBook/issues/1595
