### unicorn 6.0.0 - no more recycling Rack env / 2021-03-17 06:38 UTC¶ ↑

    This release allocates a new Rack `env' hash for every request.
    This is done for safety with internally-(thread|event)-using Rack
    apps which expect to use `env' after the normal Rack response is
    complete, but without relying on rack.hijack[1].  Thanks to
    Dirkjan Bussink <d.bussink@gmail.com> for the patch:

      https://yhbt.net/unicorn-public/66A68DD8-83EF-4C7A-80E8-3F1F7AB31670@github.com/

    The major version is bumped since:

    1) there are performance regressions for some simple Rack apps

    2) unsupported 3rd-party monkey patches which previously
       relied on this behavior may be broken (our version of
       OobGC was).

    The test suite is also more reliable on multi-core systems
    and Ruby 3.x.

    [1] thread from 2017 around rack.hijack safety:
        https://yhbt.net/unicorn-public/CAAtdryPG3nLuyo0jxfYW1YHu1Q+ZpkLkd4KdWC8vA46B5haZxw@mail.gmail.com/