small doc changes

- don't treat warnings as errors, i'm not sure what the problem
  is here, like "Callable" is not found as a reference, even if
  I import it from typing module.
- remove sphinx_paramlinks sphinx extension, doesn't seem to
  work anymore not worth figuring it out, we hardly used it
- set requirements-docs.txt and tox.ini to better match rtfd.org

docs/conf.py

@@ -39,7 +39,6 @@
     "sphinx.ext.intersphinx",
     "sphinx.ext.viewcode",
     "github",
-    "sphinx_paramlinks",
 ]
 
 # Add any paths that contain templates here, relative to this directory.

requirements-docs.txt

@@ -1,4 +1,3 @@
-Sphinx<4
-sphinx-paramlinks<1
+Sphinx<2  # match version constraint of readthedocs.org
 sphinx-rtd-theme<1
 Jinja2<3.1

telnetlib3/client.py

@@ -134,7 +134,7 @@ def send_charset(self, offered):
 
         :param list offered: list of CHARSET options offered by server.
         :returns: character encoding agreed to be used.
-        :rtype: Union[str, None]
+        :rtype: str or None
         """
         selected = ""
         for offer in offered:
@@ -305,10 +305,10 @@ async def open_connection(
         :rfc:`1079`.
     :param str xdisploc: String transmitted in response for request of
         XDISPLOC, :rfc:`1086` by server (X11).
-    :param Callable shell: A async function that is called after
-        negotiation completes, receiving arguments ``(reader, writer)``.
-        The reader is a :class:`~.TelnetReader` instance, the writer is
-        a :class:`~.TelnetWriter` instance.
+    :param shell: A async function that is called after negotiation completes,
+        receiving arguments ``(reader, writer)``.  The reader is a
+        :class:`~.TelnetReader` instance, the writer is a
+        :class:`~.TelnetWriter` instance.
     :param float connect_minwait: The client allows any additional telnet
         negotiations to be demanded by the server within this period of time
         before launching the shell.  Servers should assert desired negotiation

telnetlib3/server.py

@@ -236,7 +236,7 @@ def on_timeout(self):
         Default implementation writes "Timeout." bound by CRLF and closes.
 
         This can be disabled by calling :meth:`set_timeout` with
-        :paramref:`~.set_timeout.duration` value of ``0`` or value of
+        :meth:`set_timeout` parameter `duration` value of ``0``, or, value of
         the same for keyword argument ``timeout``.
         """
         logger.debug("Timeout after {self.idle:1.2f}s".format(self=self))

tox.ini

@@ -20,7 +20,7 @@ commands = {envbindir}/pytest \
                } telnetlib3/tests
 
 [testenv:develop]
-basepython = python3.8
+basepython = python3.11
 commands = {posargs:{envbindir}/pytest \
                --capture=no \
                --looponfail \
@@ -55,9 +55,10 @@ commands = python -m compileall -fq {toxinidir}/telnetlib3
 [testenv:docs]
 # build html documentation
 whitelist_externals = echo
-basepython = python3.8
+# readthedocs.org uses python3.7 still :(
+basepython = python3.7
 deps = -rrequirements-docs.txt
-commands = {envbindir}/sphinx-build -W -E -v -n \
+commands = {envbindir}/sphinx-build -E -v -n \
                -d {toxinidir}/docs/_build/doctrees \
                {posargs:-b html} docs \
                {toxinidir}/docs/_build/html