fix(agent-core): search usr\bin\bash.exe paths for Git Bash on Windows

.changeset/fix-windows-git-bash-path-detection.md

@@ -0,0 +1,6 @@
+---
+"@moonshot-ai/kimi-code": patch
+"@moonshot-ai/kimi-code-sdk": patch
+---
+
+Fix Git Bash path detection on Windows by also searching `usr\bin\bash.exe` locations, which is where bash lives in many Git for Windows installations where `bin\bash.exe` does not exist.

packages/kaos/src/environment.ts

@@ -95,20 +95,25 @@ async function locateWindowsGitBash(deps: EnvironmentDeps): Promise<string> {
   if (gitExe !== undefined) {
     const inferred = inferGitBashFromGitExe(gitExe);
     if (inferred !== undefined) {
-      checked.push(inferred);
-      if (await deps.isFile(inferred)) {
-        return inferred;
+      for (const path of inferred) {
+        checked.push(path);
+        if (await deps.isFile(path)) {
+          return path;
+        }
       }
     }
   }
 
   const candidates: string[] = [
     'C:\\Program Files\\Git\\bin\\bash.exe',
+    'C:\\Program Files\\Git\\usr\\bin\\bash.exe',
     'C:\\Program Files (x86)\\Git\\bin\\bash.exe',
+    'C:\\Program Files (x86)\\Git\\usr\\bin\\bash.exe',
   ];
   const localAppData = deps.env['LOCALAPPDATA']?.trim();
   if (localAppData !== undefined && localAppData.length > 0) {
     candidates.push(`${localAppData}\\Programs\\Git\\bin\\bash.exe`);
+    candidates.push(`${localAppData}\\Programs\\Git\\usr\\bin\\bash.exe`);
   }
   for (const candidate of candidates) {
     checked.push(candidate);
@@ -123,17 +128,18 @@ async function locateWindowsGitBash(deps: EnvironmentDeps): Promise<string> {
 }
 
 // Most Git for Windows installs put `git.exe` in `<root>\cmd\git.exe`,
-// with bash at `<root>\bin\bash.exe`. Portable installs sometimes put
-// both in `<root>\bin\`. Walk back to the parent of `cmd` / `bin` and
-// re-anchor under `bin\bash.exe`.
-function inferGitBashFromGitExe(gitExe: string): string | undefined {
+// with bash at `<root>\bin\bash.exe` (a wrapper) or `<root>\usr\bin\bash.exe`
+// (the real MSYS2 shell). Walk back to the parent of `cmd` / `bin` and
+// return both candidates so the caller can try them in preference order.
+function inferGitBashFromGitExe(gitExe: string): string[] | undefined {
   const sep = gitExe.includes('\\') ? '\\' : '/';
   const parts = gitExe.split(sep);
   for (let i = parts.length - 2; i >= 0; i -= 1) {
     const segment = parts[i];
     if (segment === 'cmd' || segment === 'bin') {
       const root = parts.slice(0, i).join(sep);
-      return root.length === 0 ? `bin${sep}bash.exe` : `${root}${sep}bin${sep}bash.exe`;
+      const prefix = root.length === 0 ? '' : `${root}${sep}`;
+      return [`${prefix}bin${sep}bash.exe`, `${prefix}usr${sep}bin${sep}bash.exe`];
     }
   }
   return undefined;

packages/kaos/test/environment.test.ts

@@ -157,6 +157,18 @@ describe('detectEnvironment', () => {
     expect(env.shellPath).toBe('C:\\Program Files\\Git\\bin\\bash.exe');
   });
 
+  it('infers Git Bash from usr/bin when bin/bash.exe is missing', async () => {
+    const env = await detectEnvironment(
+      stubDeps({
+        platform: 'win32',
+        executables: { 'git.exe': 'D:\\Program Files\\Git\\cmd\\git.exe' },
+        existingPaths: ['D:\\Program Files\\Git\\usr\\bin\\bash.exe'],
+      }),
+    );
+    expect(env.shellName).toBe('bash');
+    expect(env.shellPath).toBe('D:\\Program Files\\Git\\usr\\bin\\bash.exe');
+  });
+
   it('falls back to the well-known Program Files install location', async () => {
     const env = await detectEnvironment(
       stubDeps({
@@ -167,6 +179,16 @@ describe('detectEnvironment', () => {
     expect(env.shellPath).toBe('C:\\Program Files\\Git\\bin\\bash.exe');
   });
 
+  it('falls back to usr/bin under Program Files when bin/bash.exe is missing', async () => {
+    const env = await detectEnvironment(
+      stubDeps({
+        platform: 'win32',
+        existingPaths: ['C:\\Program Files\\Git\\usr\\bin\\bash.exe'],
+      }),
+    );
+    expect(env.shellPath).toBe('C:\\Program Files\\Git\\usr\\bin\\bash.exe');
+  });
+
   it('falls back to LOCALAPPDATA install when present', async () => {
     const env = await detectEnvironment(
       stubDeps({
@@ -178,6 +200,17 @@ describe('detectEnvironment', () => {
     expect(env.shellPath).toBe('C:\\Users\\me\\AppData\\Local\\Programs\\Git\\bin\\bash.exe');
   });
 
+it('falls back to usr/bin under LOCALAPPDATA when bin/bash.exe is missing', async () => {
+    const env = await detectEnvironment(
+      stubDeps({
+        platform: 'win32',
+        env: { LOCALAPPDATA: 'C:\\Users\\me\\AppData\\Local' },
+        existingPaths: ['C:\\Users\\me\\AppData\\Local\\Programs\\Git\\usr\\bin\\bash.exe'],
+      }),
+    );
+    expect(env.shellPath).toBe('C:\\Users\\me\\AppData\\Local\\Programs\\Git\\usr\\bin\\bash.exe');
+  });
+
   it('throws KaosShellNotFoundError when no Git Bash candidate is found', async () => {
     const error = await detectEnvironment(
       stubDeps({
@@ -209,6 +242,7 @@ describe('detectEnvironment', () => {
     );
     expect(error.message).toContain('D:\\custom\\bash.exe');
     expect(error.message).toContain('C:\\Program Files\\Git\\bin\\bash.exe');
+    expect(error.message).toContain('C:\\Program Files\\Git\\usr\\bin\\bash.exe');
   });
 
   // ── arch / version passthrough ─────────────────────────────────────