Warning, treated as error: node class 'meta' is already registered, its visitors will be overridden
Summary
When building bind-9.17.20 man pages, sphinx fails with message "node class 'meta' is already registered, its visitors will be overridden".
BIND version used
BIND 9.17.20 (Development Release)
Steps to reproduce
build documentation with latest versions of sphinx and docbuild (0.18)
What is the current bug behavior?
man pages fail to be built
What is the expected correct behavior?
man pages built
Relevant configuration files
N/A
Relevant logs and/or screenshots
Making all in doc
make[2]: Entering directory '/tmp/bind-9.17.20/doc'
Making all in .
make[3]: Entering directory '/tmp/bind-9.17.20/doc'
make[3]: Nothing to be done for 'all-am'.
make[3]: Leaving directory '/tmp/bind-9.17.20/doc'
Making all in misc
make[3]: Entering directory '/tmp/bind-9.17.20/doc/misc'
make all-am
make[4]: Entering directory '/tmp/bind-9.17.20/doc/misc'
make[4]: Nothing to be done for 'all-am'.
make[4]: Leaving directory '/tmp/bind-9.17.20/doc/misc'
make[3]: Leaving directory '/tmp/bind-9.17.20/doc/misc'
Making all in man
make[3]: Entering directory '/tmp/bind-9.17.20/doc/man'
SPHINX manpages.stamp
Warning, treated as error:
node class 'meta' is already registered, its visitors will be overridden
make[3]: *** [Makefile:976: manpages.stamp] Error 2
make[3]: Leaving directory '/tmp/bind-9.17.20/doc/man'
make[2]: *** [Makefile:442: all-recursive] Error 1
make[2]: Leaving directory '/tmp/bind-9.17.20/doc'
make[1]: *** [Makefile:614: all-recursive] Error 1
make[1]: Leaving directory '/tmp/bind-9.17.20'
make: *** [Makefile:520: all] Error 2
Possible fixes
Until man pages are updated to docutils 0.18 (or newer) standards, downgrade to docutils 0.17 (see https://github.com/sphinx-doc/sphinx/issues/9841)