This version brings several new features: tokio can now be used as a backing runtime for the async runtime, Windows is supported again, both the LTS and stable version are supported, and it's possible to use PyPlot and GTK to plot data from Rust.
New feature flags have been introduced which cause some backward-incompatibilities. Neither Julia nor CCall is available by default but the sync-rt and ccall features must be enabled respectively. Similary, async is no longer sufficient to use the async runtime, you must now pick either async-std or tokio as the backing runtime by enabling async-std-rt or tokio-rt respectively. The jlrs-derive is no longer available by default, but must now be explicitly enabled.
Another change is that Julia can now be detected automatically when building this crate. If the executable and library are available on the default search path the JULIA_DIR environment variable no longer needs to be set.
GeneratorTask has been renamed to PersistentTask. PersistentTask and AsyncTask can be implemented by library crates when the async feature is enabled, these implementations can be used by both async runtimes.