fix(run): resolve bundled binary on Windows Git Bash / MSYS2 / Cygwin

[keith-mvs]

Problem

On Windows under Git Bash (and MSYS2 / Cygwin), scripts/run never finds the
bundled binary and tries to download a non-existent release asset. Because the
launcher is wired as a PreToolUse (Grep|Bash) hook, it exits non-zero on
every tool call, surfacing as a hook error in the agent.

Root cause is platform detection:

OS="$(uname -s | tr '[:upper:]' '[:lower:]')"   # Git Bash -> "mingw64_nt-10.0-26200"

uname -s under Git Bash is MINGW64_NT-<windows-build>, not windows — and
it even embeds the Windows build number (10.0-26200), so it isn't a stable
string. The candidate loop then probes bin/lumen and bin/lumen-${OS}-${ARCH}
with no .exe, never matching the shipped bin/lumen-windows-amd64.exe, and
falls through to:

Downloading lumen v0.0.41 for mingw64_nt-10.0-26200/amd64...

which 404s (lumen-0.0.41-mingw64_nt-10.0-26200-amd64 is not a release asset).

Fix

Normalize mingw*|msys*|cygwin* (and explicit windows*) to windows, and
append .exe to the binary candidates and the download fallback path. The new
case only triggers on those uname strings, so Linux/macOS resolution is
unchanged.

Testing

Git Bash on Windows 11 (uname -s = MINGW64_NT-10.0-26200):

• scripts/run version -> prints 0.0.41, no "Downloading..." line
• echo '{}' | scripts/run hook pre-tool-use lumen -> exit 0

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes
  • Improved detection and handling of Windows-like environments (Git Bash, MSYS2, Cygwin) with enhanced binary discovery and proper executable file extension support during installation.

[coderabbitai]

📝 Walkthrough

Walkthrough

The launcher script (scripts/run) improves Windows environment detection by normalizing uname output patterns (Git Bash, MSYS2, Cygwin) to a standard OS="windows" value and setting .exe file extension. These platform details are then applied to binary candidate lookup and download path resolution.

Changes

Windows Platform and Executable Path Handling

Layer / File(s)	Summary
Windows platform detection and binary candidates scripts/run	Script detects Windows-like uname patterns and normalizes OS to "windows" while setting EXT to ".exe". Binary candidate list is updated to include OS/arch-specific filenames with the computed extension in addition to the generic fallback.
Download target path resolution scripts/run	When no existing binary is found and download begins, the initial BINARY target path is set to the OS/arch-specific filename including the platform-specific executable extension.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

Suggested reviewers

• aeneasr

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and specifically describes the main change: fixing bundled binary resolution on Windows Git Bash/MSYS2/Cygwin platforms.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Updates the scripts/run launcher to correctly detect and execute the bundled Windows binary under Git Bash/MSYS2/Cygwin-style environments.

Changes:

• Normalizes Windows-like uname outputs (mingw/msys/cygwin) to OS=windows.
• Introduces an executable suffix (.exe) for Windows-family environments so local binary discovery and download targets match packaged artifacts.

---

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[coderabbitai]

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

scripts/run (1)

55-56: ⚠️ Potential issue | 🔴 Critical | ⚡ Quick win

Windows download URL still omits .exe suffix.

Line 55 and Line 82 build ASSET without ${EXT}, so Windows still requests a non-existent asset name and fails bootstrap download on first run.

🔧 Proposed fix

-  ASSET="lumen-${VERSION#v}-${OS}-${ARCH}"
+  ASSET="lumen-${VERSION#v}-${OS}-${ARCH}${EXT}"
   URL="https://github.com/${REPO}/releases/download/${VERSION}/${ASSET}"
@@
-    ASSET="lumen-${VERSION#v}-${OS}-${ARCH}"
+    ASSET="lumen-${VERSION#v}-${OS}-${ARCH}${EXT}"
     URL="https://github.com/${REPO}/releases/download/${VERSION}/${ASSET}"

Also applies to: 82-83

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@scripts/run` around lines 55 - 56, The ASSET variable is built without the
platform-specific extension, so on Windows the download URL (constructed from
ASSET and used in URL) omits the .exe and fails; update the ASSET construction
(and any other places building ASSET, e.g., the second occurrence around where
ASSET is re-set) to append the ${EXT} variable (use
ASSET="lumen-${VERSION#v}-${OS}-${ARCH}${EXT}") and ensure the URL uses that
ASSET so Windows receives the .exe-suffixed artifact.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Outside diff comments:
In `@scripts/run`:
- Around line 55-56: The ASSET variable is built without the platform-specific
extension, so on Windows the download URL (constructed from ASSET and used in
URL) omits the .exe and fails; update the ASSET construction (and any other
places building ASSET, e.g., the second occurrence around where ASSET is re-set)
to append the ${EXT} variable (use
ASSET="lumen-${VERSION#v}-${OS}-${ARCH}${EXT}") and ensure the URL uses that
ASSET so Windows receives the .exe-suffixed artifact.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 095e5889-8ee5-4a77-8c55-6229020e8eb2

📥 Commits

Reviewing files that changed from the base of the PR and between d0dee0e and 93be76d.

📒 Files selected for processing (1)

• scripts/run