Re-building CSS/JS bundles on Incremental Build?

[nozo88]

Hello,

I just migrated to Gatsby V3, and I'm testing the Incremental Build feature on my local machine (since it's open source now).

I use DatoCMS, and the incremental builds are working great. When there isn't any node change, it doesn't rebuild anything, which is what I expect.
However, even it's not rebuilding the HTML pages, it still takes a while to execute the step "Building production JavaScript and CSS bundles"

This is an example output:

success onPostBootstrap - 0.081s
info bootstrap finished - 13.931s
success write out requires - 0.004s
success Building production JavaScript and CSS bundles - 22.769s
success Building HTML renderer - 7.376s
info There are no new or changed html files to build.
success onPostBuild - 0.001s
info Done building in 44.623000372 sec

My question is: Why does it re-build the JavaScript and CSS bundles when there isn't any change i.e. any new HTML generated? Can't that step be optimized as well?

It takes more than 40 seconds to build the site (when nothing is changed), which is a lot.

Thanks