Rust applications hosted on crates.io can be installed locally to
~/.cargo/bin with the cargo install command. Among other
things this makes it easier to augment Cargo with new subcommands:
when a binary named e.g. cargo-foo is found in $PATH it can be
invoked as cargo foo.
Crates with wildcard (*) dependencies will emit warnings when
published. In 1.6 it will no longer be possible to publish
crates with wildcard dependencies.
Target specifications support a no_default_libraries
setting that controls whether -nodefaultlibs is passed to the
linker, and in turn the is_like_windows setting no longer affects
the -nodefaultlibs flag.
When evaluating expressions at compile-time that are not
compile-time constants (const-evaluating expressions in non-const
contexts), incorrect code such as overlong bitshifts and arithmetic
overflow will generate a warning instead of an error,
delaying the error until runtime. This will allow the
const-evaluator to be expanded in the future backwards-compatibly.