Have you read the Contributing Guidelines on issues?

• I have read the Contributing Guidelines on issues.

Prerequisites

• I'm using the latest version of Docusaurus.
• I have tried the npm run clear or yarn clear command.
• I have tried rm -rf node_modules yarn.lock package-lock.json and re-installing packages.
• I have tried creating a repro with https://new.docusaurus.io.
• I have read the console error message carefully (if applicable).

Description

Hi guys!

Since this morning we get the following error, when we try to run docusaurus build.

[cause]: Error: Failed to compile due to Webpack errors.
× Module not found: Can't resolve '@mermaid-js/layout-elk' in '/Users/gylxan/docusaurus-project/node_modules/.pnpm/@docusaurus+theme-mermaid@3.9.0_@docusaurus+faster@3.9.0_@docusaurus+types@3.9.0_@swc+c_58aaeca4b2b6f99a4ff81e7112e57ee4/node_modules/@docusaurus/theme-mermaid/lib/client'
╭─[139:24]
137 │                     return [
138 │                         4,
139 │                         import('@mermaid-js/layout-elk')
·                         ────────────────────────────────
140 │                     ];
141 │                 case 1:
╰────

I think this belongs to #11357.

We are using docusaurus with the experimental_faster future flag.

Any idea what is the problem here?

Reproducible demo

No response

Trying currently to build a codesandbox to show the error

Steps to reproduce

1. Configure future flag experimental_faster: true
2. Install @docusarus/faster and @docusaurus/theme-mermaid
3. Build docusaurus with docusaurus build

Expected behavior

Resolving the named optional dependency, which is not installed, should not lead to a failing build

Actual behavior

Resolving the optional dependency, which is not installed, leads to a failing build

Your environment

Self-service

• I'd be willing to fix this bug myself.