Rules in 49.6: Major Issues Uncovered

Discussion
1

Title: Investigating Cursor Rules in 49.6: Major Issues Uncovered

Cursor rules in 49.6 are behaving inconsistently for me, so I conducted deep testing to understand their functionality. I discovered reproducible issues that severely impact context management, making rules unreliable for workflows like task creation.

Major Discoveries:

  1. Auto Attached Rules Don’t Load: Rules for specific file types (e.g., *.py or *.txt) often fail to apply when you open, edit, or reference files (e.g., @file.py). For example, a rule to add comments (e.g., # Rule Applied) to Python files rarely works, even with correct setup in .cursor/rules. This bug (Bug 1) means your custom formatting or context instructions are frequently ignored, disrupting file-specific workflows.
  2. Always Rules Are Unstable: Rules set to apply universally (e.g., adding a header like # Always Rule to all responses) work briefly but drop off in longer sessions. In a 20-prompt test, the header was missing in 18 responses, often failing after the first or second prompt. This bug (Bug 2) makes consistent context unreliable, as rules vanish unpredictably during extended use.

Actions Taken: I’ve filed two bug reports in the Bug Reports section:

If you’ve experienced these issues, please reply to the bug reports, by confirming you have experienced these issues. This will help Cursor understand this issue is widespread.

Testing Details: I’ll reply with a detailed test summary outlining the methodology and results for those interested.

Discussion: Please share your experiences with rules in Cursor 49.6 so we can build a more accurate picture of how they’re working for users. Are rules applying inconsistently for you, or have you found workarounds? Let’s collaborate to understand the user experience!

Note: Testing done in Cursor 49.6, Gemini 2.5, Windows. Procedural agent errors also noted.

2

Title: Verification Instructions for Cursor Rules Bugs in 49.6

Overview: These instructions allow Cursor 49.6 users to verify two critical bugs in .mdc rules (Gemini 2.5 agent mode): Bug 1 (Auto Attached rules failing to load) and Bug 2 (Always rules unstable in long sessions). Follow the steps to replicate and confirm.

Bug 1: Auto Attached Rule Loading Failure

Description: Auto Attached rules for specific file types (e.g., *.txt) often fail to apply when opening or referencing files, despite correct setup.

Verification Steps:

  1. Create .cursor/rules/test.mdc:
    ---
globs: *.txt
type: Auto Attached
---
Add comment: "# Test Rule" to text files.
  2. Create test.txt: “Test content.”
  3. Open Cursor 49.6, start an agent session (Gemini 2.5).
  4. Open test.txt.
  5. Submit prompt: “Modify test.txt to add a line.”
  6. Check if “# Test Rule” appears in the modified test.txt or output.

Expected Result: The comment “# Test Rule” is consistently added to test.txt modifications.

Actual Result to Verify: In most attempts, “# Test Rule” is missing, indicating the rule failed to load or apply.

Notes: Try multiple times and with different file types (e.g., *.py). Failures are frequent across .cursor/rules and workspace root.

Bug 2: Always Rule Stability Failure

Description: Always rules apply initially but frequently fail in longer sessions, missing headers in responses.

Verification Steps:

  1. Create .cursor/rules/core.mdc:
    ---
type: Always
---
Add header: "# Core Rule" to all AI responses.
  2. Open Cursor 49.6, start an agent session (Gemini 2.5).
  3. Submit 10 diverse prompts in sequence (e.g., “List files,” “What day is it?”, “Modify @test.txt”, “Explain Python lists”).
  4. Check each response for the “# Core Rule” header.

Expected Result: The “# Core Rule” header appears in every response.

Actual Result to Verify: The header is missing in most responses (e.g., 8/10 prompts), often starting after the first or second prompt, showing intermittent failure.

Notes: Test in a single session to mimic extended use. The pattern (e.g., missing, present, missing) may appear early.

Environment:

  • Cursor Version: 49.6
  • Model: Gemini 2.5
  • OS: Windows (likely applicable to other OS)

Reporting: If you confirm these issues, reply to the bug reports:

Tested: Oct 26-28, 2024