The layer creation itself looks a bit more complex, but this is due to
how altering the presence of timestamps changes the type signature of the
formatter. The main improvements are that we now only initialise the
registry in a single location, and the log filter reload handle has a
single type signature (whereas previously its type signature depended on
the configuration).
Requires a minimum of tracing-subscriber 0.2.12, which added this feature.
Part of zcash/zcash#4668.
The tracing crate is initialized with an optional log path, and will
either start a background thread for non-blocking log writing, or write
directly to standard output with ANSI encoding.
C preprocessor macros are used to emulate the Rust macros natively
provided by the tracing crate. They handle the creation of static
tracing callsites, and ensure that the correct file and line number
information is used for each logging site.
This enables IDE integration to work (which requires the Cargo.toml to
be in the repo root).
"make clean" no longer runs "cargo clean", because IDE integrations hold
locks on files within the Rust build directory, and an error inside
"cargo clean" error would prevent "make clean" from completing (and
removing other files).