2.1.0: sphinx warnings (`reference target not found` and other)

[kloczek]

On building my packages I'm using sphinx-build command with -n switch which shows warmings about missing references. These are not critical issues.
There are other type of warnings as well

Here is the output with warnings:

+ /usr/bin/sphinx-build -n -T -b man doc build/sphinx/man
Running Sphinx v4.5.0
making output directory... done
WARNING: html_static_path entry '_static' does not exist
building [mo]: targets for 0 po files that are out of date
building [man]: all manpages
updating environment: [new config] 5 added, 0 changed, 0 removed
reading sources... [100%] user_guide
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/build/lib.linux-x86_64-3.8/MySQLdb/_exceptions.py:docstring of MySQLdb._exceptions.DataError:1: WARNING: duplicate object description of MySQLdb._exceptions.DataError, other instance in MySQLdb, use :noindex: for one of them
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/build/lib.linux-x86_64-3.8/MySQLdb/_exceptions.py:docstring of MySQLdb._exceptions.DatabaseError:1: WARNING: duplicate object description of MySQLdb._exceptions.DatabaseError, other instance in MySQLdb, use :noindex: for one of them
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/build/lib.linux-x86_64-3.8/MySQLdb/_exceptions.py:docstring of MySQLdb._exceptions.Error:1: WARNING: duplicate object description of MySQLdb._exceptions.Error, other instance in MySQLdb, use :noindex: for one of them
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/build/lib.linux-x86_64-3.8/MySQLdb/_exceptions.py:docstring of MySQLdb._exceptions.IntegrityError:1: WARNING: duplicate object description of MySQLdb._exceptions.IntegrityError, other instance in MySQLdb, use :noindex: for one of them
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/build/lib.linux-x86_64-3.8/MySQLdb/_exceptions.py:docstring of MySQLdb._exceptions.InterfaceError:1: WARNING: duplicate object description of MySQLdb._exceptions.InterfaceError, other instance in MySQLdb, use :noindex: for one of them
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/build/lib.linux-x86_64-3.8/MySQLdb/_exceptions.py:docstring of MySQLdb._exceptions.InternalError:1: WARNING: duplicate object description of MySQLdb._exceptions.InternalError, other instance in MySQLdb, use :noindex: for one of them
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/build/lib.linux-x86_64-3.8/MySQLdb/_exceptions.py:docstring of MySQLdb._exceptions.NotSupportedError:1: WARNING: duplicate object description of MySQLdb._exceptions.NotSupportedError, other instance in MySQLdb, use :noindex: for one of them
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/build/lib.linux-x86_64-3.8/MySQLdb/_exceptions.py:docstring of MySQLdb._exceptions.OperationalError:1: WARNING: duplicate object description of MySQLdb._exceptions.OperationalError, other instance in MySQLdb, use :noindex: for one of them
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/build/lib.linux-x86_64-3.8/MySQLdb/_exceptions.py:docstring of MySQLdb._exceptions.ProgrammingError:1: WARNING: duplicate object description of MySQLdb._exceptions.ProgrammingError, other instance in MySQLdb, use :noindex: for one of them
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/build/lib.linux-x86_64-3.8/MySQLdb/_exceptions.py:docstring of MySQLdb._exceptions.Warning:1: WARNING: duplicate object description of MySQLdb._exceptions.Warning, other instance in MySQLdb, use :noindex: for one of them
looking for now-outdated files... none found
pickling environment... done
checking consistency... done
writing... python-mysqldb.3 { user_guide MySQLdb MySQLdb.constants FAQ } <unknown>:1: WARNING: py:class reference target not found: datetime.date
<unknown>:1: WARNING: py:class reference target not found: datetime.time
<unknown>:1: WARNING: py:class reference target not found: datetime.datetime
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/doc/MySQLdb.rst:12: WARNING: py:mod reference target not found: connections
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/build/lib.linux-x86_64-3.8/MySQLdb/connections.py:docstring of MySQLdb.connections.Connection:1: WARNING: py:class reference target not found: _mysql.connection
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/doc/MySQLdb.rst:20: WARNING: py:mod reference target not found: converters
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/doc/MySQLdb.rst:28: WARNING: py:mod reference target not found: cursors
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/build/lib.linux-x86_64-3.8/MySQLdb/cursors.py:docstring of MySQLdb.cursors.Cursor:1: WARNING: py:class reference target not found: MySQLdb.cursors.CursorStoreResultMixIn
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/build/lib.linux-x86_64-3.8/MySQLdb/cursors.py:docstring of MySQLdb.cursors.Cursor:1: WARNING: py:class reference target not found: MySQLdb.cursors.CursorTupleRowsMixIn
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/build/lib.linux-x86_64-3.8/MySQLdb/cursors.py:docstring of MySQLdb.cursors.Cursor:1: WARNING: py:class reference target not found: MySQLdb.cursors.BaseCursor
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/doc/MySQLdb.rst:36: WARNING: py:mod reference target not found: times
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/doc/MySQLdb.rst:44: WARNING: py:mod reference target not found: _mysql
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/doc/MySQLdb.rst:52: WARNING: py:mod reference target not found: _exceptions
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/doc/MySQLdb.constants.rst:4: WARNING: py:mod reference target not found: constants
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/doc/MySQLdb.constants.rst:12: WARNING: py:mod reference target not found: CLIENT
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/doc/MySQLdb.constants.rst:20: WARNING: py:mod reference target not found: CR
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/doc/MySQLdb.constants.rst:28: WARNING: py:mod reference target not found: ER
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/doc/MySQLdb.constants.rst:36: WARNING: py:mod reference target not found: FIELD_TYPE
/home/tkloczko/rpmbuild/BUILD/mysqlclient-2.1.0/doc/MySQLdb.constants.rst:44: WARNING: py:mod reference target not found: FLAG
done
build succeeded, 30 warnings.