Backend-specific option ignored

ALL software version info

holoviews: 1.14.3 matplotlib: 3.4.2 bokeh: 2.3.2

Description of expected behavior and the observed behavior

Disclaimer: I’m a new user and I had to dive straight pretty deep to support my use case, API misuse is not unlikely.

When setting backend-specific options for a non-default backend, the calls to options() seem to override each-other.

Complete, minimal, self-contained example code that reproduces the issue

import holoviews as hv
backend = 'bokeh'
# If the backend that is actually used is the default (i.e. bokeh), the bug disappears
hv.extension('matplotlib', 'bokeh')
print(hv.Store.current_backend)

# The 2nd options() call seems to override the first one
x = hv.Curve([1,2,3]).options(interpolation='steps-pre', backend=backend).options(color='red', backend=backend)
hv.output(x, backend=backend)

# When setting both options at once, the bug disappears
x = hv.Curve([1,2,3]).options(interpolation='steps-pre', color='red', backend=backend)
hv.output(x, backend=backend)

Screenshots or screencasts of the bug in action

[douglas-raillard-arm]

I’ll see what I can do wrt to PR, as there is a bunch of other things I’d like to give a go at fixing. It may take a (long) while though, as I need to seek legal approval from my company first.

[jlstevens]

Actually, Store is exposed at the top level and I would be happy with this context manager living there:

with hv.Store.backend('bokeh'):
   ...