feat: add reference for RUST_BACKTRACE environment variable

[siketyan]

Summary

Added an environment variable RUST_BACKTRACE to the CLI reference.

See biomejs/biome#8647 for the implementation

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[coderabbitai]

Walkthrough

This pull request updates documentation: it adds a new RUST_BACKTRACE environment-variable subsection (description and example) to the user reference and inserts matching FOOTER documentation in the codegen source. It also changes the BIOME_BINARY example fence to use a shell-language code block. There are no functional code changes or API/declaration modifications.

Pre-merge checks and finishing touches

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The pull request title clearly and concisely describes the main change: adding documentation for the RUST_BACKTRACE environment variable.
Description check	✅ Passed	The description is directly related to the changeset, clearly explaining that it adds RUST_BACKTRACE to the CLI reference documentation.

✨ Finishing touches

• 📝 Generate docstrings

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📜 Recent review details

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 6779cb7 and e8d085a.

📒 Files selected for processing (2)

• codegen/src/env_variables.rs
• src/content/docs/reference/environment_variables.md

🚧 Files skipped from review as they are similar to previous changes (1)

• codegen/src/env_variables.rs

🧰 Additional context used

📓 Path-based instructions (1)

src/**/!(en)/**/*.md

📄 CodeRabbit inference engine (CONTRIBUTING.md)

For translated pages, if a translated page doesn't exist yet, point links to the English version

Files:

• src/content/docs/reference/environment_variables.md

🧠 Learnings (1)

📚 Learning: 2025-11-28T01:34:31.084Z

Learnt from: CR
Repo: biomejs/website PR: 0
File: CONTRIBUTING.md:0-0
Timestamp: 2025-11-28T01:34:31.084Z
Learning: Set the BIOME_VERSION environment variable when running codegen commands (e.g., BIOME_VERSION=2.0.0 pnpm codegen all)

Applied to files:

• src/content/docs/reference/environment_variables.md

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (1)

• GitHub Check: test

🔇 Additional comments (2)

src/content/docs/reference/environment_variables.md (2)

26-29: Code fence formatting improvement.

The shift from an unspecified fence to shell improves syntax highlighting for readers. Good attention to detail.

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31-37: New RUST_BACKTRACE documentation is clear and well‑structured.

The description accurately explains the purpose, and the example is practical. Follows the established pattern nicely.

Since the file header notes this is auto-generated by codegen/src/env_variables.rs, please confirm that these changes originated from the codegen source rather than manual edits to this file.

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_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[coderabbitai]

Actionable comments posted: 1

📜 Review details

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 2b31ed4 and 6779cb7.

📒 Files selected for processing (2)

• codegen/src/env_variables.rs
• src/content/docs/reference/environment_variables.md

🧰 Additional context used

📓 Path-based instructions (1)

src/**/!(en)/**/*.md

📄 CodeRabbit inference engine (CONTRIBUTING.md)

For translated pages, if a translated page doesn't exist yet, point links to the English version

Files:

• src/content/docs/reference/environment_variables.md

🧠 Learnings (1)

📚 Learning: 2025-11-28T01:34:31.084Z

Learnt from: CR
Repo: biomejs/website PR: 0
File: CONTRIBUTING.md:0-0
Timestamp: 2025-11-28T01:34:31.084Z
Learning: Set the BIOME_VERSION environment variable when running codegen commands (e.g., BIOME_VERSION=2.0.0 pnpm codegen all)

Applied to files:

• codegen/src/env_variables.rs
• src/content/docs/reference/environment_variables.md

🪛 markdownlint-cli2 (0.18.1)

src/content/docs/reference/environment_variables.md

35-35: Fenced code blocks should have a language specified

(MD040, fenced-code-language)

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (5)

• GitHub Check: Redirect rules - biomejs
• GitHub Check: Header rules - biomejs
• GitHub Check: Pages changed - biomejs
• GitHub Check: test
• GitHub Check: code-quality