Webpack error with `markdown-it` and `ucmicro`

[rambip]

While running bundle exec rake assets:precompile, I got this error:

Shakapacker::Compiler - Slow setup for development

Prepare JS assets with either:
1. Running `bin/shakapacker-dev-server`
2. Set `compile` to false in shakapacker.yml and run `bin/shakapacker -w`
I, [2025-10-07T10:49:07.218213 #9353]  INFO -- : Compiling...
I, [2025-10-07T10:49:34.136191 #9353]  INFO -- : Compiled all packs in /Users/antoninp/Documents/decidim-app/public/decidim-packs
E, [2025-10-07T10:49:34.136277 #9353] ERROR -- : ⚠️ WARNING
Setting 'useContentHash' to 'false' in the production environment (specified by NODE_ENV environment variable) is not allowed!
Content hashes get added to the filenames regardless of setting useContentHash in 'shakapacker.yml' to false.

DEPRECATION WARNING [import]: Sass @import rules are deprecated and will be removed in Dart Sass 3.0.0.

More info and automated migrator: https://sass-lang.com/d/import

  ╷
1 │ @import "stylesheets/decidim/scopes/scopes-custom.scss";
  │         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  ╵
    - 1:9  root stylesheet

DEPRECATION WARNING [import]: Sass @import rules are deprecated and will be removed in Dart Sass 3.0.0.

More info and automated migrator: https://sass-lang.com/d/import

  ╷
1 │ @import "stylesheets/decidim/decidim_awesome/awesome_iframe/iframe";
  │         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  ╵
    - 1:9  root stylesheet

DEPRECATION WARNING [import]: Sass @import rules are deprecated and will be removed in Dart Sass 3.0.0.

More info and automated migrator: https://sass-lang.com/d/import

  ╷
1 │ @import "stylesheets/decidim/decidim_awesome/admin/admin_accountability";
  │         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  ╵
    - 1:9  root stylesheet

DEPRECATION WARNING [import]: Sass @import rules are deprecated and will be removed in Dart Sass 3.0.0.

More info and automated migrator: https://sass-lang.com/d/import
...

It is an undocumented issue, I was not able to see any documentation for it.
The way I fixed was to downgrade markdown-it to 13.0
The error then disappeared.

Versions

Before downgrading:

• version of markdown-it: 14.1.0
• version of uc.micro: 1.0.6

After downgrading:

• version of markdown-it 13.0.1
• version of uc.micro: 1.0.6

Note

I know that @Stef-Rousset had version 14.1.0, without having the same error.