VLT 6.0.0a15-a21 seems to break Volto (for me) locally after reinstall/rebuild with latest Cookieplone [Solved]

Estimated cause: a former second pnpm install kept a second VLT elsewhere leading to conflicting react processes.

one error of many in the browser console contained in particular:

Hooks can only be called inside the body of a function component.
...
3. You might have more than one copy of React in the same app."

Finally I used a plain pnpm list command in the project root to figure this out.

It lists a dependency to another VLT version installed elsewere (maybe globally)

Legend: production dependency, optional only, dev only

/Users/astro

dependencies:
@kitconcept/volto-light-theme 6.0.0-alpha.16
yarn 1.22.22

but actually @kitconcept/volto-light-theme 6.0.0-alpha.21 was requested in the source.

@kitconcept/volto-light-theme 6.0.0-alpha.16 could not be found in my project files.

Then:

pnpm remove @kitconcept/volto-light-theme
pnpm remove yarn

removed the dependency

When rerun pnpm list -> result was nothing

After make frontend-install, ran make backend-start & make frontend-start in two terminals
and TADA!

VLT now works in version 6.0.0a21