fix: add git-based fallback for file search on Linux (#257)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

src/main/ipc/filesystem-list-files.test.ts

@@ -1,8 +1,9 @@
 import { describe, expect, it, vi, beforeEach } from 'vitest'
 
-const { spawnMock, resolveAuthorizedPathMock } = vi.hoisted(() => ({
+const { spawnMock, resolveAuthorizedPathMock, checkRgAvailableMock } = vi.hoisted(() => ({
   spawnMock: vi.fn(),
-  resolveAuthorizedPathMock: vi.fn()
+  resolveAuthorizedPathMock: vi.fn(),
+  checkRgAvailableMock: vi.fn()
 }))
 
 vi.mock('child_process', () => ({
@@ -13,6 +14,10 @@ vi.mock('./filesystem-auth', () => ({
   resolveAuthorizedPath: resolveAuthorizedPathMock
 }))
 
+vi.mock('./rg-availability', () => ({
+  checkRgAvailable: checkRgAvailableMock
+}))
+
 import { listQuickOpenFiles } from './filesystem-list-files'
 import { EventEmitter } from 'events'
 import type { Store } from '../persistence'
@@ -36,6 +41,7 @@ describe('filesystem-list-files', () => {
   beforeEach(() => {
     vi.clearAllMocks()
     resolveAuthorizedPathMock.mockImplementation(async (path) => path)
+    checkRgAvailableMock.mockResolvedValue(true)
   })
 
   it('merges normal files and env files and filters correctly', async () => {
@@ -104,4 +110,115 @@ describe('filesystem-list-files', () => {
 
     expect(result).toEqual(['valid.ts'])
   })
+
+  describe('git ls-files fallback', () => {
+    it('falls back to git ls-files when rg is not available', async () => {
+      checkRgAvailableMock.mockResolvedValue(false)
+
+      let callIndex = 0
+      const gitP1 = createMockProcess()
+      const gitP2 = createMockProcess()
+
+      spawnMock.mockImplementation((cmd: string) => {
+        if (cmd === 'git') {
+          callIndex++
+          return callIndex === 1 ? gitP1 : gitP2
+        }
+        return createMockProcess()
+      })
+
+      const storeMock = {} as unknown as Store
+      const promise = listQuickOpenFiles('/mock/root', storeMock)
+
+      setTimeout(() => {
+        ;(gitP1.stdout as unknown as EventEmitter).emit('data', 'src/index.ts\n')
+        ;(gitP1.stdout as unknown as EventEmitter).emit('data', 'package.json\n')
+        ;(gitP1.stdout as unknown as EventEmitter).emit('data', 'node_modules/dep/index.js\n')
+        gitP1.emit('close')
+
+        ;(gitP2.stdout as unknown as EventEmitter).emit('data', '.env.local\n')
+        gitP2.emit('close')
+      }, 10)
+
+      const result = await promise
+
+      // Verify rg was never called
+      const rgCalls = spawnMock.mock.calls.filter((call) => call[0] === 'rg')
+      expect(rgCalls.length).toBe(0)
+
+      // Verify git ls-files was called
+      const gitCalls = spawnMock.mock.calls.filter((call) => call[0] === 'git')
+      expect(gitCalls.length).toBe(2)
+      expect(gitCalls[0][1]).toContain('ls-files')
+
+      // Should include valid files and filter node_modules
+      expect(result).toContain('src/index.ts')
+      expect(result).toContain('package.json')
+      expect(result).toContain('.env.local')
+      expect(result).not.toContain('node_modules/dep/index.js')
+    })
+
+    it('git fallback applies hidden dir blocklist', async () => {
+      checkRgAvailableMock.mockResolvedValue(false)
+
+      const gitP1 = createMockProcess()
+      const gitP2 = createMockProcess()
+      let callIndex = 0
+
+      spawnMock.mockImplementation((cmd: string) => {
+        if (cmd === 'git') {
+          callIndex++
+          return callIndex === 1 ? gitP1 : gitP2
+        }
+        return createMockProcess()
+      })
+
+      const storeMock = {} as unknown as Store
+      const promise = listQuickOpenFiles('/mock/root', storeMock)
+
+      setTimeout(() => {
+        ;(gitP1.stdout as unknown as EventEmitter).emit('data', '.next/cache/1.js\n')
+        ;(gitP1.stdout as unknown as EventEmitter).emit('data', '.vscode/settings.json\n')
+        ;(gitP1.stdout as unknown as EventEmitter).emit('data', '.github/workflows/ci.yml\n')
+        ;(gitP1.stdout as unknown as EventEmitter).emit('data', 'valid.ts\n')
+        gitP1.emit('close')
+
+        gitP2.emit('close')
+      }, 10)
+
+      const result = await promise
+
+      expect(result).toEqual(['.github/workflows/ci.yml', 'valid.ts'])
+    })
+
+    it('does not fall back to git when rg is available', async () => {
+      checkRgAvailableMock.mockResolvedValue(true)
+
+      const p1 = createMockProcess()
+      const p2 = createMockProcess()
+
+      spawnMock.mockImplementation((_cmd, args: string[]) => {
+        if (args.includes('**/.env*')) {
+          return p2
+        }
+        return p1
+      })
+
+      const storeMock = {} as unknown as Store
+      const promise = listQuickOpenFiles('/mock/root', storeMock)
+
+      setTimeout(() => {
+        ;(p1.stdout as unknown as EventEmitter).emit('data', '/mock/root/file.ts\n')
+        p1.emit('close')
+        p2.emit('close')
+      }, 10)
+
+      const result = await promise
+
+      expect(result).toEqual(['file.ts'])
+      // git should never have been called
+      const gitCalls = spawnMock.mock.calls.filter((call) => call[0] === 'git')
+      expect(gitCalls.length).toBe(0)
+    })
+  })
 })

src/main/ipc/filesystem-list-files.ts

@@ -2,6 +2,7 @@ import { spawn } from 'child_process'
 import { relative, sep } from 'path'
 import type { Store } from '../persistence'
 import { resolveAuthorizedPath } from './filesystem-auth'
+import { checkRgAvailable } from './rg-availability'
 
 // Why: We use --hidden to surface dotfiles users commonly edit (e.g. .env,
 // .github workflows, .eslintrc) but must still exclude non-editable hidden
@@ -46,6 +47,15 @@ function shouldIncludeQuickOpenPath(path: string): boolean {
 export async function listQuickOpenFiles(rootPath: string, store: Store): Promise<string[]> {
   const authorizedRootPath = await resolveAuthorizedPath(rootPath, store)
 
+  // Why: checking rg availability upfront avoids a race condition where
+  // spawn('rg') emits 'close' before 'error' on some platforms, causing
+  // the handler to resolve with empty results before the git fallback
+  // can run. The result is cached after the first check.
+  const rgAvailable = await checkRgAvailable()
+  if (!rgAvailable) {
+    return listFilesWithGit(authorizedRootPath)
+  }
+
   // Why: We try fast string slicing first (O(1) per file), but fall back to
   // path.relative() if the rg output doesn't start with the expected prefix.
   // This handles edge cases where symlinks, bind mounts, Windows junctions,
@@ -168,3 +178,85 @@ export async function listQuickOpenFiles(rootPath: string, store: Store): Promis
 
   return Array.from(files)
 }
+
+/**
+ * Fallback file lister using git ls-files. Used when rg is not available.
+ *
+ * Why two git ls-files calls: the first lists tracked + untracked-but-not-ignored
+ * files (mirrors rg --files --hidden with gitignore respect). The second specifically
+ * surfaces .env* files that are typically gitignored but users frequently need in
+ * quick-open (mirrors the second rg call with --no-ignore-vcs).
+ */
+function listFilesWithGit(rootPath: string): Promise<string[]> {
+  const files = new Set<string>()
+
+  const runGitLsFiles = (args: string[]): Promise<void> => {
+    return new Promise((resolve) => {
+      let buf = ''
+      let done = false
+      const finish = (): void => {
+        if (done) {
+          return
+        }
+        done = true
+        clearTimeout(timer)
+        resolve()
+      }
+
+      const processLine = (line: string): void => {
+        if (line.charCodeAt(line.length - 1) === 13 /* \r */) {
+          line = line.substring(0, line.length - 1)
+        }
+        if (!line) {
+          return
+        }
+        if (shouldIncludeQuickOpenPath(line)) {
+          files.add(line)
+        }
+      }
+
+      // Why: git ls-files outputs paths relative to cwd, so we set cwd to
+      // rootPath and use the output directly — no prefix stripping needed.
+      const child = spawn('git', ['ls-files', ...args], {
+        cwd: rootPath,
+        stdio: ['ignore', 'pipe', 'pipe']
+      })
+      child.stdout.setEncoding('utf-8')
+      child.stdout.on('data', (chunk: string) => {
+        buf += chunk
+        let start = 0
+        let newlineIdx = buf.indexOf('\n', start)
+        while (newlineIdx !== -1) {
+          processLine(buf.substring(start, newlineIdx))
+          start = newlineIdx + 1
+          newlineIdx = buf.indexOf('\n', start)
+        }
+        buf = start < buf.length ? buf.substring(start) : ''
+      })
+      child.stderr.on('data', () => {
+        /* drain */
+      })
+      child.once('error', () => {
+        finish()
+      })
+      child.once('close', () => {
+        if (buf) {
+          processLine(buf)
+        }
+        finish()
+      })
+      const timer = setTimeout(() => child.kill(), 10000)
+    })
+  }
+
+  return Promise.all([
+    // Why: --cached lists tracked files, --others lists untracked files,
+    // --exclude-standard respects .gitignore. Together this mirrors
+    // rg --files --hidden (which respects gitignore by default).
+    runGitLsFiles(['--cached', '--others', '--exclude-standard']),
+    // Why: surfaces .env* files that are typically gitignored. --others
+    // without --exclude-standard lists all untracked files; the pathspec
+    // restricts output to .env* only. Mirrors the rg --no-ignore-vcs call.
+    runGitLsFiles(['--others', '--', '**/.env*'])
+  ]).then(() => Array.from(files))
+}

src/main/ipc/filesystem-search-git.test.ts

@@ -0,0 +1,185 @@
+import { describe, expect, it, vi, beforeEach } from 'vitest'
+
+const { spawnMock } = vi.hoisted(() => ({
+  spawnMock: vi.fn()
+}))
+
+vi.mock('child_process', () => ({
+  spawn: spawnMock
+}))
+
+import { searchWithGitGrep } from './filesystem-search-git'
+import { EventEmitter } from 'events'
+import type { ChildProcess } from 'child_process'
+
+function createMockProcess(): ChildProcess {
+  const p = new EventEmitter() as unknown as ChildProcess
+  ;(p as unknown as Record<string, unknown>).stdout = new EventEmitter()
+  ;(
+    (p as unknown as Record<string, unknown>).stdout as EventEmitter & {
+      setEncoding: () => void
+    }
+  ).setEncoding = vi.fn()
+  ;(p as unknown as Record<string, unknown>).stderr = new EventEmitter()
+  ;(p as unknown as Record<string, unknown>).kill = vi.fn()
+  return p
+}
+
+describe('filesystem-search-git', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('parses git grep output and finds matches', async () => {
+    const proc = createMockProcess()
+    spawnMock.mockReturnValue(proc)
+
+    const promise = searchWithGitGrep('/mock/root', { query: 'hello', rootPath: '/mock/root' }, 100)
+
+    setTimeout(() => {
+      ;(proc.stdout as unknown as EventEmitter).emit(
+        'data',
+        'src/index.ts\x005:  console.log("hello world")\n'
+      )
+      ;(proc.stdout as unknown as EventEmitter).emit('data', 'src/main.ts\x0012:  return "hello"\n')
+      proc.emit('close')
+    }, 10)
+
+    const result = await promise
+
+    expect(result.files).toHaveLength(2)
+    expect(result.totalMatches).toBe(2)
+    expect(result.truncated).toBe(false)
+
+    expect(result.files[0].relativePath).toBe('src/index.ts')
+    expect(result.files[0].matches[0]).toEqual({
+      line: 5,
+      column: 16,
+      matchLength: 5,
+      lineContent: '  console.log("hello world")'
+    })
+
+    expect(result.files[1].relativePath).toBe('src/main.ts')
+    expect(result.files[1].matches[0].line).toBe(12)
+  })
+
+  it('finds multiple matches per line', async () => {
+    const proc = createMockProcess()
+    spawnMock.mockReturnValue(proc)
+
+    const promise = searchWithGitGrep('/mock/root', { query: 'ab', rootPath: '/mock/root' }, 100)
+
+    setTimeout(() => {
+      ;(proc.stdout as unknown as EventEmitter).emit('data', 'file.txt\x001:ab cd ab ef ab\n')
+      proc.emit('close')
+    }, 10)
+
+    const result = await promise
+
+    expect(result.files).toHaveLength(1)
+    expect(result.totalMatches).toBe(3)
+    expect(result.files[0].matches).toEqual([
+      { line: 1, column: 1, matchLength: 2, lineContent: 'ab cd ab ef ab' },
+      { line: 1, column: 7, matchLength: 2, lineContent: 'ab cd ab ef ab' },
+      { line: 1, column: 13, matchLength: 2, lineContent: 'ab cd ab ef ab' }
+    ])
+  })
+
+  it('respects maxResults and sets truncated', async () => {
+    const proc = createMockProcess()
+    spawnMock.mockReturnValue(proc)
+
+    const promise = searchWithGitGrep('/mock/root', { query: 'x', rootPath: '/mock/root' }, 2)
+
+    setTimeout(() => {
+      ;(proc.stdout as unknown as EventEmitter).emit(
+        'data',
+        'a.ts\x001:x\n' + 'b.ts\x001:x\n' + 'c.ts\x001:x\n'
+      )
+      proc.emit('close')
+    }, 10)
+
+    const result = await promise
+
+    expect(result.totalMatches).toBe(2)
+    expect(result.truncated).toBe(true)
+  })
+
+  it('passes correct flags for case-insensitive fixed-string search', async () => {
+    const proc = createMockProcess()
+    spawnMock.mockReturnValue(proc)
+
+    const promise = searchWithGitGrep(
+      '/mock/root',
+      { query: 'test', rootPath: '/mock/root', caseSensitive: false, useRegex: false },
+      100
+    )
+
+    setTimeout(() => proc.emit('close'), 10)
+    await promise
+
+    const gitArgs = spawnMock.mock.calls[0][1] as string[]
+    expect(gitArgs).toContain('-i')
+    expect(gitArgs).toContain('--fixed-strings')
+    expect(gitArgs).not.toContain('--extended-regexp')
+  })
+
+  it('passes correct flags for regex whole-word search', async () => {
+    const proc = createMockProcess()
+    spawnMock.mockReturnValue(proc)
+
+    const promise = searchWithGitGrep(
+      '/mock/root',
+      {
+        query: 'foo',
+        rootPath: '/mock/root',
+        caseSensitive: true,
+        useRegex: true,
+        wholeWord: true
+      },
+      100
+    )
+
+    setTimeout(() => proc.emit('close'), 10)
+    await promise
+
+    const gitArgs = spawnMock.mock.calls[0][1] as string[]
+    expect(gitArgs).toContain('-w')
+    expect(gitArgs).toContain('--extended-regexp')
+    expect(gitArgs).not.toContain('-i')
+    expect(gitArgs).not.toContain('--fixed-strings')
+  })
+
+  it('returns empty result when git grep spawn fails', async () => {
+    const proc = createMockProcess()
+    spawnMock.mockReturnValue(proc)
+
+    const promise = searchWithGitGrep('/mock/root', { query: 'test', rootPath: '/mock/root' }, 100)
+
+    setTimeout(() => proc.emit('error', new Error('spawn git ENOENT')), 10)
+
+    const result = await promise
+
+    expect(result.files).toHaveLength(0)
+    expect(result.totalMatches).toBe(0)
+  })
+
+  it('skips lines without null separator', async () => {
+    const proc = createMockProcess()
+    spawnMock.mockReturnValue(proc)
+
+    const promise = searchWithGitGrep('/mock/root', { query: 'ok', rootPath: '/mock/root' }, 100)
+
+    setTimeout(() => {
+      // A line without \0 should be skipped (e.g. git header output)
+      ;(proc.stdout as unknown as EventEmitter).emit('data', 'no-null-here:1:ok\n')
+      ;(proc.stdout as unknown as EventEmitter).emit('data', 'valid.ts\x003:ok\n')
+      proc.emit('close')
+    }, 10)
+
+    const result = await promise
+
+    expect(result.files).toHaveLength(1)
+    expect(result.files[0].relativePath).toBe('valid.ts')
+  })
+})

src/main/ipc/filesystem-search-git.ts

@@ -0,0 +1,220 @@
+import { spawn } from 'child_process'
+import { join } from 'path'
+import type { SearchOptions, SearchResult, SearchFileResult } from '../../shared/types'
+
+const SEARCH_TIMEOUT_MS = 15000
+
+function normalizeRelativePath(path: string): string {
+  return path.replace(/[\\/]+/g, '/').replace(/^\/+/, '')
+}
+
+// Why: esbuild's parser chokes on regex literals containing brace/bracket
+// character classes, so we escape special chars with a simple loop instead.
+const REGEX_SPECIAL = '.*+?^${}()|[]\\'
+function escapeRegexSource(str: string): string {
+  let out = ''
+  for (let i = 0; i < str.length; i++) {
+    out += REGEX_SPECIAL.includes(str[i]) ? `\\${str[i]}` : str[i]
+  }
+  return out
+}
+
+/**
+ * Convert a user-facing glob pattern into a git pathspec.
+ *
+ * Why: rg globs like `*.ts` match at any directory depth, but a bare git
+ * pathspec `*.ts` only matches in the repo root. Wrapping with `:(glob)` and
+ * prepending `** /` for patterns without a path separator replicates rg's
+ * recursive-by-default behaviour.
+ */
+function toGitGlobPathspec(glob: string, exclude?: boolean): string {
+  const needsRecursive = !glob.includes('/')
+  const pattern = needsRecursive ? `**/${glob}` : glob
+  return exclude ? `:(exclude,glob)${pattern}` : `:(glob)${pattern}`
+}
+
+/**
+ * Fallback text search using git grep. Used when rg is not available.
+ *
+ * Why: On Linux, rg may not be installed or may not be in PATH when the app
+ * is launched from a desktop entry (which inherits a minimal system PATH).
+ * git grep is always available since this is a git-focused app.
+ */
+export function searchWithGitGrep(
+  rootPath: string,
+  args: SearchOptions,
+  maxResults: number
+): Promise<SearchResult> {
+  return new Promise((resolve) => {
+    // Why: --untracked searches untracked (but not ignored) files in addition
+    // to tracked ones, matching rg's default behaviour of respecting gitignore.
+    // Why: -I skips binary files (mirrors rg's default). --null uses \0 as
+    // the filename delimiter so filenames with colons parse unambiguously.
+    // --no-recurse-submodules is needed because users may have
+    // submodule.recurse=true in their git config, which conflicts with
+    // --untracked and would cause git grep to fail.
+    const gitArgs: string[] = [
+      '-c',
+      'submodule.recurse=false',
+      'grep',
+      '-n',
+      '-I',
+      '--null',
+      '--no-color',
+      '--untracked'
+    ]
+
+    if (!args.caseSensitive) {
+      gitArgs.push('-i')
+    }
+    if (args.wholeWord) {
+      gitArgs.push('-w')
+    }
+    if (!args.useRegex) {
+      gitArgs.push('--fixed-strings')
+    } else {
+      gitArgs.push('--extended-regexp')
+    }
+
+    gitArgs.push('-e', args.query, '--')
+
+    let hasPathspecs = false
+    if (args.includePattern) {
+      for (const pat of args.includePattern
+        .split(',')
+        .map((s) => s.trim())
+        .filter(Boolean)) {
+        gitArgs.push(toGitGlobPathspec(pat))
+        hasPathspecs = true
+      }
+    }
+    if (args.excludePattern) {
+      for (const pat of args.excludePattern
+        .split(',')
+        .map((s) => s.trim())
+        .filter(Boolean)) {
+        gitArgs.push(toGitGlobPathspec(pat, true))
+        hasPathspecs = true
+      }
+    }
+    // Why: when no include patterns are given, git grep needs a pathspec to
+    // search the working tree. '.' means "everything under cwd".
+    if (!hasPathspecs) {
+      gitArgs.push('.')
+    }
+
+    const fileMap = new Map<string, SearchFileResult>()
+    let totalMatches = 0
+    let truncated = false
+    let stdoutBuffer = ''
+    let done = false
+
+    // Build a JS regex to locate all submatch positions within each matched
+    // line. git grep only reports the first match per line; we need byte
+    // offsets and lengths for every occurrence to populate SearchMatch[].
+    let pattern = args.useRegex ? args.query : escapeRegexSource(args.query)
+    if (args.wholeWord) {
+      pattern = `\\b${pattern}\\b`
+    }
+    const matchRegex = new RegExp(pattern, `g${args.caseSensitive ? '' : 'i'}`)
+
+    const resolveOnce = (): void => {
+      if (done) {
+        return
+      }
+      done = true
+      clearTimeout(killTimeout)
+      resolve({
+        files: Array.from(fileMap.values()),
+        totalMatches,
+        truncated
+      })
+    }
+
+    const processLine = (line: string): void => {
+      if (!line || totalMatches >= maxResults) {
+        return
+      }
+
+      // Why: with --null -n the output format is filename\0linenum:content.
+      // The null byte separates the filename unambiguously (colons in
+      // filenames would otherwise break parsing).
+      const nullIdx = line.indexOf('\0')
+      if (nullIdx === -1) {
+        return
+      }
+      const relPath = normalizeRelativePath(line.substring(0, nullIdx))
+      const rest = line.substring(nullIdx + 1)
+      const colonIdx = rest.indexOf(':')
+      if (colonIdx === -1) {
+        return
+      }
+
+      const lineNum = parseInt(rest.substring(0, colonIdx), 10)
+      if (isNaN(lineNum)) {
+        return
+      }
+      const lineContent = rest.substring(colonIdx + 1).replace(/\n$/, '')
+
+      const absPath = join(rootPath, relPath)
+      let fileResult = fileMap.get(absPath)
+      if (!fileResult) {
+        fileResult = { filePath: absPath, relativePath: relPath, matches: [] }
+        fileMap.set(absPath, fileResult)
+      }
+
+      // Find all match positions within the line
+      matchRegex.lastIndex = 0
+      let m: RegExpExecArray | null
+      while ((m = matchRegex.exec(lineContent)) !== null) {
+        fileResult.matches.push({
+          line: lineNum,
+          column: m.index + 1,
+          matchLength: m[0].length,
+          lineContent
+        })
+        totalMatches++
+        if (totalMatches >= maxResults) {
+          truncated = true
+          child.kill()
+          break
+        }
+        // Prevent infinite loop on zero-length regex matches
+        if (m[0].length === 0) {
+          matchRegex.lastIndex++
+        }
+      }
+    }
+
+    const child = spawn('git', gitArgs, {
+      cwd: rootPath,
+      stdio: ['ignore', 'pipe', 'pipe']
+    })
+    child.stdout.setEncoding('utf-8')
+    child.stdout.on('data', (chunk: string) => {
+      stdoutBuffer += chunk
+      const lines = stdoutBuffer.split('\n')
+      stdoutBuffer = lines.pop() ?? ''
+      for (const l of lines) {
+        processLine(l)
+      }
+    })
+    child.stderr.on('data', () => {
+      /* drain */
+    })
+    child.once('error', () => {
+      resolveOnce()
+    })
+    child.once('close', () => {
+      if (stdoutBuffer) {
+        processLine(stdoutBuffer)
+      }
+      resolveOnce()
+    })
+
+    const killTimeout = setTimeout(() => {
+      truncated = true
+      child.kill()
+    }, SEARCH_TIMEOUT_MS)
+  })
+}

src/main/ipc/filesystem.ts

@@ -35,6 +35,8 @@ import {
 } from './filesystem-auth'
 import { listQuickOpenFiles } from './filesystem-list-files'
 import { registerFilesystemMutationHandlers } from './filesystem-mutations'
+import { searchWithGitGrep } from './filesystem-search-git'
+import { checkRgAvailable } from './rg-availability'
 
 const MAX_FILE_SIZE = 5 * 1024 * 1024 // 5MB
 const DEFAULT_SEARCH_MAX_RESULTS = 2000
@@ -180,6 +182,15 @@ export function registerFilesystemHandlers(store: Store): void {
     )
     const searchKey = `${event.sender.id}:${rootPath}`
 
+    // Why: checking rg availability upfront avoids a race condition where
+    // spawn('rg') emits 'close' before 'error' on some platforms, causing
+    // the handler to resolve with empty results before the git-grep
+    // fallback can run. The result is cached after the first check.
+    const rgAvailable = await checkRgAvailable()
+    if (!rgAvailable) {
+      return searchWithGitGrep(rootPath, args, maxResults)
+    }
+
     return new Promise((resolvePromise) => {
       const rgArgs: string[] = [
         '--json',

src/main/ipc/rg-availability.ts

@@ -0,0 +1,29 @@
+import { spawn } from 'child_process'
+
+// Why: when rg is not installed, spawn('rg', ...) emits both 'error' and
+// 'close' events but their ordering is non-deterministic across Node versions
+// and platforms. If 'close' fires first the handler resolves with empty
+// results before the 'error' handler can trigger the git-grep fallback.
+// Checking rg availability once upfront (cached) avoids the race entirely.
+let rgAvailableCache: boolean | null = null
+
+export function checkRgAvailable(): Promise<boolean> {
+  if (rgAvailableCache !== null) {
+    return Promise.resolve(rgAvailableCache)
+  }
+  return new Promise((resolve) => {
+    const child = spawn('rg', ['--version'], { stdio: 'ignore' })
+    child.once('error', () => {
+      rgAvailableCache = false
+      resolve(false)
+    })
+    child.once('close', (code) => {
+      if (rgAvailableCache !== null) {
+        // error handler already resolved
+        return
+      }
+      rgAvailableCache = code === 0
+      resolve(rgAvailableCache)
+    })
+  })
+}