fix-bug

# Fix OpenROAD Bug You are fixing a bug related to **$ARGUMENTS**. ## 1. Understand the bug If `$ARGUMENTS` is a GitHub issue number: ```bash gh issue view $ARGUMENTS --repo The-OpenROAD-Project/OpenROAD \ --json title,body,labels,comments ``` Extract from the issue: - **Error string** (e.g. `GPL-0305`, `DRT-0001`) -- search for the exact message ID - **Module** -- infer from labels or error prefix - **Steps to reproduce** -- look for attached scripts, Tcl commands, or tarballs - **Stack trace** -- if a crash, identify the faulting function If `$ARGUMENTS` is an error code, search for it directly: ```bash grep -rn "ERROR_CODE" src/MODULE/src/ ``` ## 2. Trace the root cause Follow OpenROAD's "trace bugs upstream" principle: find where the bad data is **created**, not where it is **reported**. 1. Find the error message source: ```bash grep -rn "ERROR_ID" src/ ``` 2. Read the surrounding code to understand the condition that triggers it 3. Trace the data flow backward -- who sets the offending value? 4. Identify the actual bug location (often in a different function/file from where the error is reported) **Critical constraint**: Never modify files under `src/sta/`. OpenSTA is managed upstream. If the root cause is in OpenSTA, report this finding instead of patching it. ## 3. Implement the fix Follow the coding practices in `docs/agents/coding.md`. Pay special attention to `int64_t` for area calculations and removing unreachable code after `error()` or `throw`. ## 4. Create regression test Every bug fix needs a test that reproduces the exact failure mode from the issue (same error code, same stack frame, same condition) so a future regression is caught immediately. Use the **add-test** skill (`.agents/skills/add-test/SKILL.md`) for the full workflow: writing the test, generating golden files, and registering in both CMake and Bazel. ## 5. Format and commit ```bash # Format changed C++ files (NEVER format src/sta/* or *.i files) clang-format -i <changed-cpp-files> # Stage and commit with DCO sign-off git add <changed-files> git commit -s -m "MODULE: fix BRIEF_DESCRIPTION Fixes #ISSUE_NUMBER" ``` ## 6. Verify - [ ] Test passes: `cd src/MODULE/test && ./regression -R TEST_NAME` - [ ] No unintended changes: `git diff HEAD` - [ ] Test registered in both CMake and Bazel - [ ] No `src/sta/` files modified - [ ] C++ files formatted with clang-format - [ ] Commit is signed off (`-s`)