make docs warning for event 'autodoc-process-signature' threw an exception

[viniarck]

If you try to make docs, there's a warning stating that an exception is being thrown even though the command succeeds, @jab1982 has found this issue recently, it seems related to sphinx failing to derive the type hints when trying to format the signature:

❯ make
make clean
make[1]: Entering directory '/home/viniarck/repos/python-openflow/docs'
rm -rf pyof.*
rm -rf _build/*
make[1]: Leaving directory '/home/viniarck/repos/python-openflow/docs'
make dirhtml
make[1]: Entering directory '/home/viniarck/repos/python-openflow/docs'
sphinx-apidoc -o . ../pyof/ -d10 -M -T
Creating file ./pyof.rst.
Creating file ./pyof.foundation.rst.
Creating file ./pyof.v0x01.rst.
Creating file ./pyof.v0x01.asynchronous.rst.
Creating file ./pyof.v0x01.common.rst.
Creating file ./pyof.v0x01.controller2switch.rst.
Creating file ./pyof.v0x01.symmetric.rst.
Creating file ./pyof.v0x04.rst.
Creating file ./pyof.v0x04.asynchronous.rst.
Creating file ./pyof.v0x04.common.rst.
Creating file ./pyof.v0x04.controller2switch.rst.
Creating file ./pyof.v0x04.symmetric.rst.
sed -i "/Submodules/,+1d" *.rst
sed -i "/Subpackages/,+1d" *.rst
sphinx-build -b dirhtml -d _build/doctrees   . _build/dirhtml
Running Sphinx v3.1.2
making output directory... done
loading intersphinx inventory from https://docs.python.org/3/objects.inv...
building [mo]: targets for 0 po files that are out of date
building [dirhtml]: targets for 19 source files that are out of date
updating environment: [new config] 19 added, 0 changed, 0 removed
reading sources... [100%] references
WARNING: error while formatting signature for pyof.foundation.base.GenericBitMask: Handler <function record_typehints at 0x7fa116e1c700> for event 'autodoc-process-signature' threw an ex
ception
WARNING: error while formatting signature for pyof.v0x01.common.action.ActionType: Handler <function record_typehints at 0x7fa116e1c700> for event 'autodoc-process-signature' threw an ex
ception
WARNING: error while formatting signature for pyof.v0x01.common.flow_match.FlowWildCards: Handler <function record_typehints at 0x7fa116e1c700> for event 'autodoc-process-signature' thre
w an exception
WARNING: error while formatting signature for pyof.v0x01.common.phy_port.PortConfig: Handler <function record_typehints at 0x7fa116e1c700> for event 'autodoc-process-signature' threw an
exception
WARNING: error while formatting signature for pyof.v0x01.common.phy_port.PortFeatures: Handler <function record_typehints at 0x7fa116e1c700> for event 'autodoc-process-signature' threw a
n exception
WARNING: error while formatting signature for pyof.v0x01.common.phy_port.PortState: Handler <function record_typehints at 0x7fa116e1c700> for event 'autodoc-process-signature' threw an e
xception
WARNING: error while formatting signature for pyof.v0x01.controller2switch.features_reply.Capabilities: Handler <function record_typehints at 0x7fa116e1c700> for event 'autodoc-process-s
ignature' threw an exception
WARNING: error while formatting signature for pyof.v0x01.controller2switch.flow_mod.FlowModFlags: Handler <function record_typehints at 0x7fa116e1c700> for event 'autodoc-process-signatu
re' threw an exception
WARNING: error while formatting signature for pyof.v0x04.common.port.PortConfig: Handler <function record_typehints at 0x7fa116e1c700> for event 'autodoc-process-signature' threw an exce
ption
WARNING: error while formatting signature for pyof.v0x04.common.port.PortFeatures: Handler <function record_typehints at 0x7fa116e1c700> for event 'autodoc-process-signature' threw an ex
ception
WARNING: error while formatting signature for pyof.v0x04.common.port.PortState: Handler <function record_typehints at 0x7fa116e1c700> for event 'autodoc-process-signature' threw an excep
tion
WARNING: error while formatting signature for pyof.v0x04.controller2switch.features_reply.Capabilities: Handler <function record_typehints at 0x7fa116e1c700> for event 'autodoc-process-s
ignature' threw an exception
WARNING: error while formatting signature for pyof.v0x04.controller2switch.flow_mod.FlowModFlags: Handler <function record_typehints at 0x7fa116e1c700> for event 'autodoc-process-signatu
re' threw an exception
WARNING: error while formatting signature for pyof.v0x04.controller2switch.meter_mod.MeterFlags: Handler <function record_typehints at 0x7fa116e1c700> for event 'autodoc-process-signatur
e' threw an exception
WARNING: error while formatting signature for pyof.v0x04.controller2switch.multipart_reply.GroupCapabilities: Handler <function record_typehints at 0x7fa116e1c700> for event 'autodoc-pro
cess-signature' threw an exception
looking for now-outdated files... none found
pickling environment... done
checking consistency... done
preparing documents... done
writing output... [100%] references
generating indices...  genindex py-modindexdone
writing additional pages...  searchdone
copying static files... ... done
copying extra files... done
dumping search index in English (code: en)... done
dumping object inventory... done
build succeeded, 15 warnings.

The HTML pages are in _build/dirhtml.

Build finished. The HTML pages are in _build/dirhtml.
make[1]: Leaving directory '/home/viniarck/repos/python-openflow/docs'