chore: version packages

src/session.ts

@@ -68,6 +68,7 @@ import {
   getClaudeCliVersion,
   getClaudeBinaryPath,
   spawnPtyWithHelperRepair,
+  resolveLocalShell,
 } from './utils/index.js';
 import {
   MAX_TERMINAL_BUFFER_SIZE,
@@ -1898,8 +1899,9 @@ export class Session extends EventEmitter {
 
     this._resetBuffers();
 
-    // Use user's default shell or bash
-    const shell = process.env.SHELL || '/bin/bash';
+    // Use user's default shell, falling back to a shell that actually exists.
+    // Shared with the tmux pane command so both paths launch the same binary.
+    const shell = resolveLocalShell();
     console.log(
       '[Session] Starting shell session with:',
       shell + (this._useMux ? ` (with ${this._mux!.backend})` : '')

src/tmux-manager.ts

@@ -71,6 +71,7 @@ import {
   resolveCodexDir,
   resolveGeminiDir,
   resolveAntigravityDir,
+  resolveLocalShell,
 } from './utils/index.js';
 import type {
   TerminalMultiplexer,
@@ -773,7 +774,13 @@ export function buildSpawnCommand(options: {
   if (options.mode === 'antigravity') {
     return buildAntigravityCommand(options.antigravityConfig);
   }
-  return '$SHELL';
+  // #208: NOT the literal '$SHELL'. This string is embedded in the `bash -c "…"`
+  // argument of the respawn-pane line, which execSync runs through `/bin/sh -c`,
+  // so a `$SHELL` here is expanded by the SERVER process's shell against the
+  // SERVER process's env — empty in containers and system systemd units, leaving
+  // the pane command ending in a dangling `&&` ("syntax error: unexpected end of
+  // file", pane dead on arrival). Resolve it in Node and quote the result.
+  return shellescape(resolveLocalShell());
 }
 
 /**

src/utils/index.ts

@@ -26,6 +26,7 @@ export { isSafePushEndpoint } from './push-endpoint-validation.js';
 export { stringSimilarity, fuzzyPhraseMatch, todoContentHash } from './string-similarity.js';
 export { assertNever } from './type-safety.js';
 export { wrapWithNice } from './nice-wrapper.js';
+export { resolveLocalShell } from './shell-resolver.js';
 export { findClaudeDir, getAugmentedPath, getClaudeCliVersion, getClaudeBinaryPath } from './claude-cli-resolver.js';
 export { spawnPtyWithHelperRepair } from './node-pty-repair.js';
 export { resolveOpenCodeDir } from './opencode-cli-resolver.js';

src/utils/shell-resolver.ts

@@ -0,0 +1,78 @@
+/**
+ * @fileoverview Resolve a real, launchable login shell for `mode: 'shell'` sessions.
+ *
+ * The tmux pane command for a local shell session used to be the literal string
+ * `$SHELL`. That string is embedded in the `bash -c "…"` argument of the
+ * `respawn-pane` line, which `execSync` hands to `/bin/sh -c` — so `$SHELL` was
+ * expanded by the SERVER process's shell (not the pane's), against the SERVER
+ * process's env. Containers and system-level systemd units do not set `SHELL`,
+ * so the expansion produced an empty string and the pane command ended in a
+ * dangling `&&`:
+ *
+ *   bash -c "cd \"/case\" && ulimit … && export … && "
+ *   -> bash: -c: line 1: syntax error: unexpected end of file
+ *
+ * The pane then died instantly (status 2) while tmux creation itself reported
+ * success, which is exactly what issue #208 saw. Resolving the shell HERE, in
+ * Node, removes the shell-expansion layer entirely and guarantees a non-empty
+ * absolute path.
+ *
+ * @module utils/shell-resolver
+ */
+
+import { accessSync, constants } from 'node:fs';
+import { userInfo } from 'node:os';
+
+/** Last-resort shells, in preference order. `/bin/sh` exists on every POSIX host. */
+const FALLBACK_SHELLS = ['/bin/bash', '/bin/zsh', '/bin/sh'];
+
+/**
+ * Shells that exist and are executable but immediately exit — a service account's
+ * passwd entry commonly points at one, which would look identical to the crash
+ * this module exists to prevent.
+ */
+const NON_INTERACTIVE_SHELLS = new Set(['nologin', 'false', 'true', 'sync']);
+
+function isUsableShell(candidate: string): boolean {
+  if (!candidate.startsWith('/')) return false;
+  const base = candidate.slice(candidate.lastIndexOf('/') + 1);
+  if (NON_INTERACTIVE_SHELLS.has(base)) return false;
+  try {
+    accessSync(candidate, constants.X_OK);
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+/**
+ * Resolve an absolute path to an interactive shell, preferring the user's own.
+ *
+ * Order: `$SHELL` -> the passwd entry -> `/bin/bash` -> `/bin/zsh` -> `/bin/sh`.
+ * Every candidate must be an absolute path to an executable that is not a
+ * nologin-style stub. Always returns a non-empty string.
+ */
+export function resolveLocalShell(): string {
+  const candidates: string[] = [];
+
+  const envShell = process.env.SHELL?.trim();
+  if (envShell) candidates.push(envShell);
+
+  try {
+    // Throws when the uid has no /etc/passwd entry (common for `--user` containers).
+    const passwdShell = userInfo().shell?.trim();
+    if (passwdShell) candidates.push(passwdShell);
+  } catch {
+    /* no passwd entry — fall through to the static fallbacks */
+  }
+
+  candidates.push(...FALLBACK_SHELLS);
+
+  for (const candidate of candidates) {
+    if (isUsableShell(candidate)) return candidate;
+  }
+
+  // Nothing was verifiable (exotic/read-restricted image). /bin/sh is still the
+  // best guess and is far better than emitting an empty command.
+  return '/bin/sh';
+}