Unit 1.26.1 release

[Valentin V. Bartenev]

Hi,

I'm glad to announce a new release of NGINX Unit.

This is a minor bugfix release that aims to eliminate some annoying regressions
revealed after the release of Unit 1.26.0 two weeks ago.

Notably, the shared OPcache implementation in that release required introducing
some major architectural changes, but our functional tests didn't catch some
regressions caused by these changes.  Still, thanks to our active community,
the issues were reported shortly after the release, and now we can provide an
updated version.  We will also improve our functional testing to avoid such
regressions in the future.

The most painful and visible one was that sometimes Unit daemon couldn't
completely exit, leaving some zombie processes.  However, the second attempt to
stop it always succeeded.  Also, some DragonFly BSD kernel interfaces are
seemingly broken, preventing the Unit daemon from functioning, so we disabled
their use when compiling for DragonFly BSD.


Changes with Unit 1.26.1                                         02 Dec 2021

    *) Bugfix: occasionally, the Unit daemon was unable to fully terminate;
       the bug had appeared in 1.26.0.

    *) Bugfix: a prototype process could crash on an application process
       exit; the bug had appeared in 1.26.0.

    *) Bugfix: the router process crashed on reconfiguration if "access_log"
       was configured without listeners.

    *) Bugfix: a segmentation fault occurred in the PHP module if chdir() or
       fastcgi_finish_request() was called in the OPcache preloading script.

    *) Bugfix: fatal errors on DragonFly BSD; the bug had appeared in
       1.26.0.


To know more about the bunch of changes introduced in Unit 1.26 and the roadmap
for 1.27, please see the previous announcement:

 - https://mailman.nginx.org/pipermail/unit/2021-November/000288.html

Thank you again for keeping your finger on the pulse, reporting issues and
submitting feature requests via our GitHub issue tracker:

 - https://github.com/nginx/unit/issues

Stay tuned!

  wbr, Valentin V. Bartenev