I was following the guide to build the API reference. Took me a while to debug the make html to build api reference in apidoc folder on macOS. Error message:

sed -i 's/:class:`plotly.graph_objects/:class:`plotly.graph_objs/g' ../../packages/python/plotly/plotly/graph_objs/*.py
sed: 1: "../../packages/python/p ...": invalid command code .
make: *** [html] Error 1

The problem was that the sed commands in the apidoc/Makefile don't work on macOS. You'll need to edit the Makefile to replace commands like

sed -i 's/:class:`plotly.graph_objects/:class:`plotly.graph_objs/g' ../../packages/python/plotly/plotly/graph_objs/*.py

with

sed -i '' -e 's/:class:`plotly.graph_objects/:class:`plotly.graph_objs/g' ../../packages/python/plotly/plotly/graph_objs/*.py

Why?

On the OSX version of sed, the -i option expects an extension argument so your command is actually parsed as the extension argument and the file path is interpreted as the command code.

See this thread for details.