GHC 8.10.1-rc1 is now available

The GHC team is happy to announce the availability of the first release
candidate of GHC 8.10.1. Source and binary distributions are
available at the usual place.

GHC 8.10.1 will bring a number of new features including:

  • The new UnliftedNewtypes extension allowing newtypes around unlifted
    types.

  • The new StandaloneKindSignatures extension allows users to give
    top-level kind signatures to type, type family, and class
    declarations.

  • A new warning, -Wderiving-defaults, to draw attention to ambiguous
    deriving clauses

  • A number of improvements in code generation, including changes

  • A new GHCi command, :instances, for listing the class instances
    available for a type.

  • An upgraded Windows toolchain lifting the MAX_PATH limitation

  • A new, low-latency garbage collector.

  • Improved support profiling, including support for sending profiler
    samples to the eventlog, allowing correlation between the profile and
    other program events

This is the first and likely final release candidate. For a variety of
reasons, it comes a few weeks later than the original schedule of
release late December. However, besides a few core libraries
book-keeping issues this candidate is believed to be in good condition
for the final release. As such, the final 8.10.1 release will likely
come in two weeks.

Note that at the moment we still require that macOS Catalina users
exempt the binary distribution from the notarization requirement by
running xattr -cr . on the unpacked tree before running make install.

In addition, we are still looking for any Alpine Linux to help diagnose
the correctness issues in the Alpine binary distribution. If you use
Alpine any you can offer here would be greatly appreciated.

Please do test this release and let us know if you encounter any other
issues.

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