grouped bar charts (Faceted or VConcat)?

I’m trying to do something like this example, but repeated across a separate dimension. I’d like to have a shared y-axis within each grouped bar chart, but I’d like to have an independent y-axis across different bar charts. (Hopefully that makes sense).

I can get something to render if I just add facets, but it will share the y-axis within each chart as well as across different charts is undesirable and ends up looking like this:

If I set resolve_scale(y='independent'), it ends up decoupling the y-axis within each chart as well as across different charts which is also undesirable:

If I try to vconcat each independent grouped bar chart, it complains that my vconcat is invalid.

Any ideas on how to accomplish what I want?

I tried to repurpose the example code to use it as example code, and it fails. Hopefully this helps explain what I’m trying to do.

My code

import altair as alt
from altair.expr import datum, if_
from vega_datasets import data

source = data.population.url

base = alt.Chart(source).mark_bar(stroke='transparent').encode(
    alt.X('gender:N', scale=alt.Scale(rangeStep=12), axis=alt.Axis(title='')),
    alt.Y('sum(people):Q', axis=alt.Axis(title='population', grid=False)),
    color=alt.Color('gender:N', scale=alt.Scale(range=["#EA98D2", "#659CCA"])),
    column='age:O'
# comment out configure functions that can't be used in a vconcat
# ).configure_view(
#     stroke='transparent'
# ).configure_axis(
#     domainWidth=0.8
).transform_filter(
    datum.year == 2000
).transform_calculate(
    'gender', if_(datum.sex == 2, 'Female', 'Male')
)

chart = alt.vconcat()
chart &= base
chart

The error

Invalid specification

    altair.vegalite.v2.api.VConcatChart->vconcat->items, validating 'anyOf'

    {'data': {'url': 'https://vega.github.io/vega-datasets/data/population.json'}, 'mark': {'type': 'bar', 'stroke': 'transparent'}, 'encoding': {'color': {'type': 'nominal', 'field': 'gender', 'scale': {'range': ['#EA98D2', '#659CCA']}}, 'column': {'type': 'ordinal', 'field': 'age'}, 'x': {'type': 'nominal', 'axis': {'title': ''}, 'field': 'gender', 'scale': {'rangeStep': 12}}, 'y': {'type': 'quantitative', 'aggregate': 'sum', 'axis': {'grid': False, 'title': 'population'}, 'field': 'people'}}, 'transform': [{'filter': '(datum.year === 2000)'}, {'calculate': "if((datum.sex === 2),'Female','Male')", 'as': 'gender'}]} is not valid under any of the given schemas

[domoritz]

Fixed in https://github.com/vega/vega-lite/pull/3965

[domoritz]

We’re going to fix this in Vega-Lite. It will be included in the next release.