Uglifier::Error: generators cannot be async

[mauriziomarini]

I have reinstalled on a fresh ubuntu

I choosed to install ruby 2.7.3, maybe this is the issue?

rbenv install 2.7.3

then, after all the required steps
bin/rails assets:precompile db:migrate RAILS_ENV=production_
Yarn executable was not detected in the system.
Download Yarn at https://yarnpkg.com/en/docs/install
rails aborted!

Uglifier::Error: generators cannot be async

[mauriziomarini]

I fixed the Gemfile:

before
gem "decidim", "0.24.2"
#gem "decidim-conferences", "0.24.2"
#gem "decidim-consultations", "0.24.2"
#gem "decidim-elections", "0.24.2"
#gem "decidim-initiatives", "0.24.2"
#gem "decidim-templates", "0.24.2"

after:
gem "decidim", "0.24.2"
#gem "decidim-conferences", "0.24.2"
#gem "decidim-consultations", "0.24.2"
#gem "decidim-elections", "0.24.2"
#gem "decidim-initiatives", "0.24.2"
#gem "decidim-templates", "0.24.2"

now the issue is solved

So the gem below gem "decidim", "0.24.2"
should commented

But

when I should decomment them?
at which step?
this is not documented, sadly
please help!