fix(remote): keep Codeman's pane command away from the remote default-shell

Handing the launch to bash verbatim exposed `"${SHELL:-/bin/sh}"` to the far
end for the first time. tmux runs a one-argument command through the remote
default-shell, not /bin/sh as the comments said, and fish refuses `${...}`:
on a fish host, or a bash login with `set -g default-shell fish`, every new
pane died with status 127. master only survived because the local sh had
already rewritten that token to this host's shell path.

Codeman's own text now goes to `/bin/sh -c` as separate tmux arguments, which
tmux execs without a shell. A commands.* override stays one argument and keeps
the default-shell it was written for: under `/bin/sh` a `source` or `[[` in an
override dies with 127 on bash and zsh hosts.

The tests read the argv tmux would receive through a real sh, so they need no
fish: every stock launch must reach /bin/sh and an override must not. The
docker half of bashCArg was pinned by nothing, so it gets its own test.

Comments that described the removed double-quote layer are corrected, and
remote-hosts.ts no longer claims overrides are seeded from the default text
or that they rescue nushell and elvish.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.changeset/remote-launch-expansion.md

@@ -0,0 +1,5 @@
+---
+"aicodeman": patch
+---
+
+Remote sessions: new sessions no longer die with `tmux: command not found` (exit 127) when the remote user's home differs from the Codeman host's. The launch line reached the local shell in double quotes, so `$HOME` and `$PATH` in the remote PATH bootstrap expanded on the Codeman host before ssh ran. Launches now reach the far end verbatim, which also means a remote session starts in the remote user's own shell rather than the Codeman host's, and a Codeman host whose `$SHELL` path does not exist on the remote no longer kills the pane. Codeman's own pane command now runs through `/bin/sh` so fish hosts keep working, while a per-host `commands.*` override still runs in the remote user's shell. Behaviour change: in a `commands.*` override, `$` now expands on the far end (remote host or container) instead of on the Codeman host, and a bare `$VAR` in a Docker `extraCreateArgs`/`extraExecArgs` value is passed to `docker` literally, so write the value out. Thanks to @Randalix for the report and the fix.

docs/remote-sessions.md

@@ -133,6 +133,24 @@ Key points:
   **login shell**, not the agent.
 - The **whole tmux invocation is a single shell-quoted ssh argument**, and the
   pane command is independently quoted, so a `remotePath` with spaces is safe.
+- **That argument reaches the far end verbatim** (#760): the launch goes to the
+  local `bash -c` in single quotes, so `$HOME`, `$PATH` and `$SHELL` are the
+  remote user's. In double quotes the local `sh` expanded them first, which sent
+  this host's home and PATH to the remote. ⚠️ Every `$` in a `commands.*` override
+  now expands on the far end too. A Docker launch is verbatim as well, so a bare
+  `$VAR` in `extraCreateArgs`/`extraExecArgs` reaches `docker` as those literal
+  characters: write the value out.
+- **tmux picks the shell by argument count** (measured on 3.4): one argument runs
+  through the remote `default-shell`, two or more are exec'd directly. Codeman's own
+  pane command is POSIX, so it goes to `/bin/sh -c` as separate arguments, and a fish
+  login shell (or a `default-shell` set in the remote `~/.tmux.conf`) never parses it:
+  fish refuses `${SHELL:-/bin/sh}` with status 127, which is a dead pane. A `commands.*`
+  override stays one argument on purpose, since it is written for the user's own shell
+  (`source` and `[[` work in bash and zsh and die under a dash `/bin/sh`).
+- **Login shells**: POSIX shells and fish work. tcsh refuses the `-i -l` pair and needs
+  a `commands.*` override per mode (`exec claude`). nushell and elvish cannot run the
+  PATH bootstrap at all, so no override helps. A `remotePath` holding an apostrophe does
+  not start under fish.
 - Connection options come from the **same `buildSshConnectionArgs(remote)`** as
   the prereq probe; `-t` is inserted right after `ssh -o BatchMode=yes`,
   preserving historical token order.

package-lock.json

@@ -63,7 +63,7 @@
         "exceljs": "4.4.0",
         "fflate": "0.8.3",
         "pixelmatch": "^6.0.0",
-        "playwright": "^1.58.0",
+        "playwright": "^1.64.1",
         "pngjs": "^7.0.0",
         "postcss": "^8.5.15",
         "prettier": "^3.4.0",
@@ -9736,50 +9736,32 @@
       }
     },
     "node_modules/playwright": {
-      "version": "1.60.0",
+      "version": "1.64.1",
-      "resolved": "https://registry.npmjs.org/playwright/-/playwright-1.60.0.tgz",
+      "resolved": "https://registry.npmjs.org/playwright/-/playwright-1.64.1.tgz",
-      "integrity": "sha512-hheHdokM8cdqCb0lcE3s+zT4t4W+vvjpGxsZlDnikarzx8tSzMebh3UiFtgqwFwnTnjYQcsyMF8ei2mCO/tpeA==",
+      "integrity": "sha512-HCrVhHr5QQuwYoswEUGTb7gGp522yflbv/ST8nF4sFWGuLjQCt17Q/EubpGGSNKYn1tsTCPZxqHhHCfVURu7UA==",
       "dev": true,
       "license": "Apache-2.0",
       "dependencies": {
-        "playwright-core": "1.60.0"
+        "playwright-core": "1.64.1"
       },
       "bin": {
         "playwright": "cli.js"
       },
       "engines": {
-        "node": ">=18"
+        "node": ">=20"
-      },
-      "optionalDependencies": {
-        "fsevents": "2.3.2"
       }
     },
     "node_modules/playwright-core": {
-      "version": "1.60.0",
+      "version": "1.64.1",
-      "resolved": "https://registry.npmjs.org/playwright-core/-/playwright-core-1.60.0.tgz",
+      "resolved": "https://registry.npmjs.org/playwright-core/-/playwright-core-1.64.1.tgz",
-      "integrity": "sha512-9bW6zvX/m0lEbgTKJ6YppOKx8H3VOPBMOCFh2irXFOT4BbHgrx5hPjwJYLT40Lu+4qtD36qKc/Hn56StUW57IA==",
+      "integrity": "sha512-BC4s8y6SEVA6Q1rSxZTto8hI1KUI3xXlHGZgvGqP4IqPdI/a6FX9H29IDNz7vKo9l21b6LfYosScPL6M3xxyDQ==",
       "dev": true,
       "license": "Apache-2.0",
       "bin": {
         "playwright-core": "cli.js"
       },
       "engines": {
-        "node": ">=18"
+        "node": ">=20"
-      }
-    },
-    "node_modules/playwright/node_modules/fsevents": {
-      "version": "2.3.2",
-      "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-2.3.2.tgz",
-      "integrity": "sha512-xiqMQR4xAeHTuB9uWm+fFRcIOgKBMiOBP+eXiyT7jsgVCq1bkVygt00oASowB7EdtpOHaaPgKt812P9ab+DDKA==",
-      "dev": true,
-      "hasInstallScript": true,
-      "license": "MIT",
-      "optional": true,
-      "os": [
-        "darwin"
-      ],
-      "engines": {
-        "node": "^8.16.0 || ^10.6.0 || >=11.0.0"
       }
     },
     "node_modules/pngjs": {

package.json

@@ -133,7 +133,7 @@
     "exceljs": "4.4.0",
     "fflate": "0.8.3",
     "pixelmatch": "^6.0.0",
-    "playwright": "^1.58.0",
+    "playwright": "^1.64.1",
     "pngjs": "^7.0.0",
     "postcss": "^8.5.15",
     "prettier": "^3.4.0",

src/docker-hosts.ts

@@ -392,7 +392,7 @@ export function isAdoptedContainer(docker: Pick<SessionDocker, 'owned'>): boolea
 /**
  * POSIX single-quote shell-escaping (end-quote, escaped-quote, restart-quote).
  * Mirror of the helper in remote-hosts.ts / tmux-manager.ts. Every dynamic value
- * interpolated into the outer `bash -c "..."` launch layer is escaped through
+ * interpolated into the `bash -c` launch layer is escaped through
  * this so a path with spaces stays a single shell token. Operator-entered fields
  * are ALSO schema-rejected for `$`/backtick (NO_SHELL_META) as defense in depth.
  */

src/remote-hosts.ts

@@ -66,10 +66,11 @@ export async function writeRemoteCases(configDir: string, cases: RemoteCase[]):
  * arrival, the #208 failure all over again (verified: `sh -c 'exec $SHELL -i -l'`
  * with SHELL unset prints `exec: -i: not found`). In practice tmux always exports
  * SHELL into a pane from its own `default-shell` option, so the command as USED
- * here is safe either way (also verified). The default matters because these
+ * here is safe either way (also verified). Quoted for a shell path containing
- * strings are the seed values a per-host `commands.*` override is edited from, and
+ * spaces. `/bin/sh` exists on every POSIX host.
- * nothing constrains where an edited one ends up running. Quoted for a shell path
+ *
- * containing spaces. `/bin/sh` exists on every POSIX host.
+ * ⚠️ This is POSIX text. fish refuses `${…}` (status 127), so a launch hands it to
+ * `/bin/sh -c`, never to the remote default-shell (`buildRemoteLaunchCommand`).
  */
 const REMOTE_LOGIN_SHELL = '"${SHELL:-/bin/sh}"';
 
@@ -80,10 +81,12 @@ const REMOTE_LOGIN_SHELL = '"${SHELL:-/bin/sh}"';
  * so a bare `exec claude` sees only sshd's minimal default PATH and dies with
  * "command not found" (exit 127).
  *
- * Shells that take neither flag (nushell, elvish, …) cannot be detected from here
+ * Shells that take neither flag cannot be detected from here the way
- * the way `loginShellArgs()` detects them locally, since the shell is whatever the
+ * `loginShellArgs()` detects them locally, since the shell is whatever the REMOTE
- * REMOTE passwd says. A host like that is what the per-host `commands.*` override
+ * passwd says. A host like that is what the per-host `commands.*` override is for
- * is for.
+ * (tcsh, which rejects `-l` combined with `-i`). It only goes so far: the PATH
+ * bootstrap below runs in the login shell first, so a shell that cannot parse
+ * `export` at all (nushell, elvish) cannot be rescued by an override.
  */
 export function remoteLoginShellCommand(command: string): string {
   return `exec ${REMOTE_LOGIN_SHELL} -i -l -c ${shellescape(command)}`;
@@ -143,8 +146,9 @@ function overlayCliCommand(mode: SessionMode, location: 'remote' | 'docker'): st
  * The per-host `commands.*` override remains the escape hatch for every mode.
  */
 export function defaultRemoteCommandForMode(mode: SessionMode): string {
-  // $SHELL, not a hardcoded bash: sshd sets it from the remote user's /etc/passwd entry, so
+  // $SHELL, not a hardcoded bash: sshd sets it from the remote user's /etc/passwd entry, and
-  // this launches their actual login shell (zsh, fish, …). `-i -l` so it sources rc files,
+  // tmux exports its default-shell as SHELL into the pane, so this launches their actual
+  // login shell, or the default-shell their tmux.conf picks (zsh, fish, …). `-i -l` so it sources rc files,
   // matching the local shell-mode launch. Not templatable as overlay data: the shell is
   // whatever the REMOTE passwd says, which is why `shell` is the one arm still written here.
   const shellCommand = `exec ${REMOTE_LOGIN_SHELL} -i -l`;

src/tmux-manager.ts

@@ -1303,10 +1303,12 @@ export function remoteTmuxLocation(remote: SessionRemote, sessionId: string): {
  * - The `set` options are scoped per-session (`set -t <name>` / server-level
  *   `set -s`), never `-g`, so they never mutate other sessions' prefix/mouse.
  * - The whole tmux invocation is a SINGLE ssh argument (the remote login shell
- *   runs it), so it is shell-quoted as one unit; the `cd && exec` command is in
+ *   runs it), so it is shell-quoted as one unit. The `cd && exec` command is the
- *   turn a single tmux argument (tmux runs it via `/bin/sh -c`), so the path is
+ *   pane command: Codeman's own text goes to `/bin/sh -c` as separate tmux
- *   shell-quoted inside it too. This keeps escaping correct through every layer
+ *   arguments, and a per-host `commands.*` override stays one argument, which
- *   even when the remote path contains spaces.
+ *   tmux hands to the remote default-shell (see the comment at `paneCommand`).
+ *   Each is shell-quoted, so escaping stays correct through every layer even
+ *   when the remote path contains spaces.
  */
 export function buildRemoteLaunchCommand(options: {
   mode: SessionMode;
@@ -1389,17 +1391,25 @@ export function buildRemoteLaunchCommand(options: {
   }
   const remoteName = remoteTmuxSessionName(sessionId);
 
-  // Innermost: the command tmux runs in the new pane. Run via `/bin/sh -c` by
+  // Innermost: the command tmux runs in the new pane. `exec` replaces the shell
-  // tmux, so the path needs shell-quoting here. `exec` replaces the shell with
+  // with the CLI so the pane PID is the agent itself.
-  // the CLI so the pane PID is the agent itself.
+  //
+  // tmux runs a ONE-argument command through the remote default-shell, which is
+  // the user's login shell, and bypasses it for two or more arguments (both
+  // measured on tmux 3.4). Codeman's own text is POSIX (`"${SHELL:-/bin/sh}"` is
+  // a parse error in fish, status 127, a dead pane on every new session), so it
+  // goes to `/bin/sh -c` as separate arguments and no login shell has to parse it.
+  // An override is the user's own text for THEIR shell: it stays one argument,
+  // because `source` and `[[` work in bash and zsh and die in a dash `/bin/sh`.
   const paneCommand = `cd ${shellescape(remote.remotePath)} && ${modeCommand}`;
+  const paneArgv = `${override ? '' : '/bin/sh -c '}${shellescape(paneCommand)}`;
 
   // The tmux command line, with `\;` separating commands so the config `set`s
   // apply on the SAME connection (and are idempotent on reattach). Options are
   // scoped per-session (`set -t <name>` / server `set -s`), NEVER `-g`, so a
   // shared remote tmux server's other sessions keep their own prefix/mouse.
   const tmuxInvocation = [
-    `tmux -L ${REMOTE_TMUX_SOCKET} new-session -A -s ${remoteName} -c ${shellescape(remote.remotePath)} ${shellescape(paneCommand)}`,
+    `tmux -L ${REMOTE_TMUX_SOCKET} new-session -A -s ${remoteName} -c ${shellescape(remote.remotePath)} ${paneArgv}`,
     `set -t ${remoteName} status off`,
     `set -t ${remoteName} mouse off`,
     `set -t ${remoteName} prefix ${NESTED_TMUX_PREFIX}`,
@@ -1574,7 +1584,7 @@ export interface DockerLaunchOptions {
  * Build the ONE `bash -c` launch string for a docker session: image-check ->
  * ensure (inspect-or-create) -> start -> `exec docker exec -it` into the durable
  * in-container tmux (resume-aware). PURE and unit-testable. The escaping survives
- * four layers: outer `bash -c "…"` (JSON.stringify at respawn-pane) -> the joined
+ * four layers: outer `bash -c '…'` (`bashCArg()` at respawn-pane) -> the joined
  * command -> `docker exec … sh -lc '<tmux>'` -> tmux `'<paneCommand>'`.
  */
 export function buildDockerLaunchCommand(opts: DockerLaunchOptions): string {
@@ -1602,8 +1612,8 @@ export function buildDockerLaunchCommand(opts: DockerLaunchOptions): string {
   } else if (resumeSessionId) {
     modeCommand = appendResumeFlag(modeCommand, mode, resumeSessionId);
   }
-  // Run by tmux via /bin/sh -c, so the path is shell-quoted here. `exec` makes the
+  // Run by tmux through the container's default-shell, so the path is shell-quoted
-  // pane PID the agent itself.
+  // here. `exec` makes the pane PID the agent itself.
   const paneCommand = `cd ${workdir} && ${modeCommand}`;
 
   // `setenv -g` primes the session id so reattaches / newly-created panes inherit
@@ -1665,11 +1675,10 @@ export function buildDockerLaunchCommand(opts: DockerLaunchOptions): string {
   const ensure = adopted
     ? `${base} inspect ${name} >/dev/null 2>&1 || { echo ${notFoundMsg}; exit 1; }`
     : `${base} inspect ${name} >/dev/null 2>&1 || ${createCommand}`;
-  // ⚠️ No double quotes and no `$(…)` in the ADOPTED arms. This whole chain is
+  // A `grep -qx` pipeline, in the single-quoted form every other line in this builder
-  // embedded in an outer `bash -c "…"`, so an unescaped `"` closes that string early,
+  // uses. This chain reaches `bash -c` verbatim now (`bashCArg()`), but it went through
-  // the rest is re-tokenized, and tmux fails to exec with a bare `execvp(3) failed`.
+  // a double-quoted layer for a long time, where a `"` closed that string early and tmux
-  // A `grep -qx` pipeline reads the same answer using only the single-quoted form
+  // failed with a bare `execvp(3) failed`, so keep it free of double quotes and `$(…)`.
-  // every other line in this builder already uses.
   const start = adopted
     ? `${base} inspect -f ${shellescape('{{.State.Running}}')} ${name} 2>/dev/null | grep -qx true || { echo ${notRunningMsg}; exit 1; }`
     : `${base} start ${name} >/dev/null 2>&1 || { echo ${startFailMsg}; exit 1; }`;
@@ -2661,7 +2670,7 @@ export class TmuxManager extends EventEmitter implements TerminalMultiplexer {
       // pane launch in /tmp, then cd inside bash against the current mount table.
       const launchCmd = remote || docker ? fullCmd : `cd ${JSON.stringify(workingDir)} && ${fullCmd}`;
       execSync(
-        `${this.tmux()} respawn-pane -k -c ${TMUX_LAUNCH_CWD} -t "${muxName}" bash -c ${JSON.stringify(launchCmd)}`,
+        `${this.tmux()} respawn-pane -k -c ${TMUX_LAUNCH_CWD} -t "${muxName}" bash -c ${bashCArg(launchCmd, !!(remote || docker))}`,
         {
           timeout: EXEC_TIMEOUT_MS,
           stdio: 'ignore',
@@ -2914,7 +2923,7 @@ export class TmuxManager extends EventEmitter implements TerminalMultiplexer {
       // -c /tmp + cd bounce — see createSession() for rationale (stale FUSE state).
       const launchCmd = remote || docker ? fullCmd : `cd ${JSON.stringify(workingDir)} && ${fullCmd}`;
       await execAsync(
-        `${this.tmux()} respawn-pane -k -c ${TMUX_LAUNCH_CWD} -t "${muxName}" bash -c ${JSON.stringify(launchCmd)}`,
+        `${this.tmux()} respawn-pane -k -c ${TMUX_LAUNCH_CWD} -t "${muxName}" bash -c ${bashCArg(launchCmd, !!(remote || docker))}`,
         {
           timeout: EXEC_TIMEOUT_MS,
         }
@@ -4663,6 +4672,24 @@ export class TmuxManager extends EventEmitter implements TerminalMultiplexer {
   }
 }
 
+/**
+ * The `bash -c` argument of a pane launch (`respawn-pane … bash -c <arg>`, run through the
+ * local sh). A remote or docker command is already quoted for the shell at the far end and
+ * must reach bash verbatim, so it goes in single quotes. Double quotes (JSON.stringify) let
+ * the local sh expand every `$` first: the PATH bootstrap of `withRemoteTmuxPath`
+ * (`$HOME/.local/bin:…:$PATH`) arrived on the remote host as this host's home and PATH, so
+ * a remote user with another home found no tmux and every new remote pane exited 127.
+ * `${SHELL:-/bin/sh}` in the remote launch was the local shell for the same reason.
+ * Local commands keep their double-quoted form.
+ *
+ * ⚠️ So nothing in a verbatim launch is expanded on this host any more, the docker client's
+ * own arguments included: a bare `$VAR` in `extraCreateArgs`/`extraExecArgs` reaches docker
+ * as those literal characters.
+ */
+function bashCArg(launchCmd: string, verbatim: boolean): string {
+  return verbatim ? shellescape(launchCmd) : JSON.stringify(launchCmd);
+}
+
 /**
  * Shell-escape a string for use as a single argument.
  * Wraps in single quotes, escaping any embedded single quotes.

src/web/schemas.ts

@@ -878,11 +878,11 @@ const RemoteCommandOverridesSchema = z
 const NO_SHELL_INJECTION = /^[^\n\r\0`]*$/;
 const noCommandSubstitution = (s: string) => !s.includes('$(');
 
-// `remotePath`/`identityFile` are shell-escaped, then the whole launch command is
+// `remotePath`/`identityFile` are shell-escaped, and a remote launch reaches `bash -c`
-// embedded via `JSON.stringify(...)` inside `bash -c "..."` (tmux-manager). That
+// single-quoted (`bashCArg()` in tmux-manager). They are also pasted into strings the
-// outer DOUBLE-quote layer re-exposes `$(...)`, backticks, and `$VAR` even though
+// far end's shells parse, and hosts stored before a launch-quoting change are read with
-// the inner value is single-quoted — so a `$(cmd)` in the path would run LOCALLY at
+// no schema, so `$` and backtick (and newline/CR/NUL) stay rejected at the boundary as
-// launch. Reject `$` and backtick (and newline/CR/NUL) entirely at the boundary.
+// defense in depth, whatever the current quoting does with them.
 const NO_SHELL_META = /^[^\n\r\0`$]*$/;
 
 export const RemoteHostSchema = z.object({
@@ -982,10 +982,10 @@ export const RemoteCaseLinkSchema = z.object({
 //
 // Docker mode is a location overlay on cases (see docs/docker-cases-plan.md),
 // the analog of the remote-SSH schemas above. `image`, `hostWorkspacePath`,
-// `containerWorkdir`, and `container` all reach the outer `bash -c "..."` launch
+// `containerWorkdir`, and `container` all reach the `bash -c` launch layer, so they
-// layer, so they carry NO_SHELL_META (rejects `$`/backtick that survive the
+// carry NO_SHELL_META (rejects `$`/backtick) exactly like remotePath/identityFile.
-// double-quote layer) exactly like remotePath/identityFile. `--privileged` and
+// `--privileged` and any docker-socket mount are structurally unrepresentable
-// any docker-socket mount are structurally unrepresentable (never accepted).
+// (never accepted).
 
 const DockerResourceLimitsSchema = z
   .object({

test/edit-history-sync.test.ts

@@ -428,14 +428,20 @@ describe('EditHistorySync', () => {
     host.append('main', editLine('t1', T0, '/w/a.ts'));
     const orig = host.read;
     let first = true;
+    let inRead!: () => void;
+    const reachedRead = new Promise<void>((r) => (inRead = r));
     host.read = async (...a) => {
       if (first) {
         first = false;
+        inRead();
         await gate;
       }
       return orig(...a);
     };
     const slow = sync.sync(local);
+    // Only once s1 holds the gate: the sessions load their stores independently, so a later one
+    // could reach the read first, take the gate and hang the loop below before `release()`.
+    await reachedRead;
     for (let i = 1; i <= MAX_LOADED_STORES + 1; i++) await sync.sync({ ...local, id: `s1-${i}` });
     release();
     expect(await slow).toEqual({ state: 'ok' });

test/remote-pane-command-shell.test.ts

@@ -0,0 +1,81 @@
+/**
+ * @fileoverview Which shell parses a remote pane command (#760).
+ *
+ * tmux runs a ONE-argument command through the remote default-shell, the user's login shell, and
+ * bypasses it for two or more arguments. Codeman's own text carries `"${SHELL:-/bin/sh}"`, a parse
+ * error in fish that kills the pane with status 127, so it must reach `/bin/sh -c` as separate
+ * arguments. A per-host `commands.*` override is the user's text for their own shell: `source` and
+ * `[[` work in bash and zsh and die under a dash `/bin/sh`, so it must stay one argument.
+ *
+ * CI has no fish, so this reads the argv tmux would receive instead: the real builder's string goes
+ * through a real sh with `ssh` and `tmux` defined as functions that report their arguments.
+ */
+import { execFileSync } from 'node:child_process';
+import { describe, expect, it } from 'vitest';
+import { listClis } from '../src/config/cli-registry/registry.js';
+import { buildRemoteLaunchCommand } from '../src/tmux-manager.js';
+import type { SessionMode, SessionRemote } from '../src/types.js';
+
+const SESSION_ID = 'abcd1234-0000-0000-0000-000000000000';
+const remote: SessionRemote = {
+  hostId: 'gpu',
+  label: 'GPU',
+  host: '10.0.0.42',
+  username: 'ubuntu',
+  remotePath: '/home/ubuntu/it is work',
+};
+
+/** The one argument ssh would send, as the login shell on the far end receives it. */
+function sshArgument(launch: string): string {
+  return execFileSync('/bin/sh', ['-c', `ssh() { for a; do l="$a"; done; printf '%s' "$l"; }; ${launch}`], {
+    encoding: 'utf8',
+  });
+}
+
+/** What follows `new-session … -c <dir>`, up to the end of that tmux command. */
+function paneArgv(launch: string): string[] {
+  const argv = execFileSync('/bin/sh', ['-c', `tmux() { printf '%s\\0' "$@"; }; ${sshArgument(launch)}`], {
+    encoding: 'utf8',
+  })
+    .split('\0')
+    .slice(0, -1);
+  const head = argv.slice(0, argv.indexOf(';'));
+  return head.slice(head.indexOf('-c', head.indexOf('new-session')) + 2);
+}
+
+const launches: Array<[string, Parameters<typeof buildRemoteLaunchCommand>[0]]> = [
+  ...listClis().map((cli): [string, Parameters<typeof buildRemoteLaunchCommand>[0]] => [
+    cli.id,
+    { mode: cli.id as SessionMode, remote, sessionId: SESSION_ID },
+  ]),
+  ['shell', { mode: 'shell', remote, sessionId: SESSION_ID }],
+  ['claude resume', { mode: 'claude', remote, sessionId: SESSION_ID, resumeSessionId: SESSION_ID }],
+  ['omp resume', { mode: 'omp', remote, sessionId: SESSION_ID, resumeSessionId: 'abc123' }],
+];
+
+describe('the shell that parses a remote pane command', () => {
+  it.each(launches)('%s: Codeman text goes to /bin/sh, never the default-shell', (_name, options) => {
+    const argv = paneArgv(buildRemoteLaunchCommand(options));
+    expect(argv.slice(0, 2)).toEqual(['/bin/sh', '-c']);
+    expect(argv).toHaveLength(3);
+    expect(argv[2]).toContain(`cd '/home/ubuntu/it is work' && `);
+  });
+
+  it('leaves an override as one argument, parsed by the remote default-shell', () => {
+    const override = 'source ~/env.sh && [[ -x ~/.local/bin/codx ]] && exec codx';
+    const argv = paneArgv(
+      buildRemoteLaunchCommand({
+        mode: 'codex',
+        remote: { ...remote, commands: { codex: override } },
+        sessionId: SESSION_ID,
+      })
+    );
+    expect(argv).toEqual([`cd '/home/ubuntu/it is work' && ${override}`]);
+  });
+
+  it('keeps the rest of the tmux chain behind the longer pane command', () => {
+    const sent = sshArgument(buildRemoteLaunchCommand({ mode: 'shell', remote, sessionId: SESSION_ID }));
+    expect(sent).toContain(String.raw` \; set -t codeman-ssh-abcd1234 status off \; `);
+    expect(sent).toMatch(/set -t codeman-ssh-abcd1234 remain-on-exit failed$/);
+  });
+});

test/remote-ssh-options.test.ts

@@ -159,7 +159,7 @@ describe('COD-107 buildRemoteLaunchCommand — threads connection args', () => {
     const path = sh('/home/ubuntu/work');
     const paneCommand = `cd ${path} && exec "\${SHELL:-/bin/sh}" -i -l`;
     const tmuxInvocation = [
-      `tmux -L codeman-remote new-session -A -s ${remoteName} -c ${path} ${sh(paneCommand)}`,
+      `tmux -L codeman-remote new-session -A -s ${remoteName} -c ${path} /bin/sh -c ${sh(paneCommand)}`,
       `set -t ${remoteName} status off`,
       `set -t ${remoteName} mouse off`,
       `set -t ${remoteName} prefix C-q`,

test/tmux-manager.test.ts

@@ -28,6 +28,20 @@ import type { MuxSession } from '../src/mux-interface.js';
 // ============================================================================
 
 // Mock child_process
+/**
+ * Runs a captured `… respawn-pane … bash -c <arg>` line through a real local sh (with a
+ * foreign HOME/PATH) and returns the string bash would get, i.e. what ssh sends on.
+ */
+async function bashArgAfterLocalShell(respawnCmd: string): Promise<string> {
+  const real = await vi.importActual<typeof import('node:child_process')>('node:child_process');
+  const at = respawnCmd.indexOf(' bash -c ');
+  expect(at).toBeGreaterThan(0);
+  return real.execFileSync('/bin/sh', ['-c', `printf '%s' ${respawnCmd.slice(at + ' bash -c '.length)}`], {
+    env: { HOME: '/local-home-xyz', PATH: '/local-path-xyz:/usr/bin:/bin' },
+    encoding: 'utf8',
+  });
+}
+
 vi.mock('node:child_process', async () => {
   const actual = await vi.importActual('node:child_process');
   return {
@@ -865,6 +879,98 @@ describe('TmuxManager (unit)', () => {
       }
     });
 
+    it('hands a remote launch to ssh with $HOME and $PATH unexpanded', async () => {
+      // respawn-pane runs `bash -c <arg>` through the local sh. In double quotes that sh
+      // expanded withRemoteTmuxPath's `$HOME/…:$PATH` to the Codeman host's values, so a
+      // remote user with another home found no tmux and the pane exited 127.
+      const NonTestTmuxManager = await importWithTmuxCommandsEnabled();
+      const nonTestManager = new NonTestTmuxManager();
+
+      try {
+        await nonTestManager.createSession({
+          sessionId: 'abc12345-1234-5678-90ab-cdef12345679',
+          workingDir: '/w',
+          mode: 'shell',
+          remote: { hostId: 'gpu-box', label: 'GPU Box', host: '10.0.0.42', username: 'ubuntu', remotePath: '/w' },
+        });
+        const launch = [...mockedExecSync.mock.calls, ...vi.mocked(exec).mock.calls]
+          .map(([cmd]) => cmd)
+          .find((cmd) => typeof cmd === 'string' && cmd.includes(' respawn-pane '));
+        const sent = await bashArgAfterLocalShell(launch as string);
+        expect(sent).toContain('ssh ');
+        expect(sent).toContain('export PATH="$HOME/');
+        expect(sent).toContain(':$PATH"; tmux ');
+        expect(sent).not.toContain('local-home-xyz');
+        expect(sent).not.toContain('local-path-xyz');
+      } finally {
+        nonTestManager.destroy();
+      }
+    });
+
+    it('respawns a remote pane with $HOME unexpanded as well', async () => {
+      const NonTestTmuxManager = await importWithTmuxCommandsEnabled();
+      const nonTestManager = new NonTestTmuxManager();
+      nonTestManager.registerSession({
+        sessionId: 'respawnremote2',
+        muxName: 'codeman-abcd8888',
+        pid: 1000,
+        createdAt: Date.now(),
+        workingDir: '/w',
+        mode: 'shell',
+        attached: false,
+      });
+
+      try {
+        await nonTestManager.respawnPane({
+          sessionId: 'respawnremote2',
+          workingDir: '/w',
+          mode: 'shell',
+          remote: { hostId: 'gpu-box', label: 'GPU Box', host: '10.0.0.42', username: 'ubuntu', remotePath: '/w' },
+        });
+        const { exec: currentExec } = await import('node:child_process');
+        const respawnCall = vi
+          .mocked(currentExec)
+          .mock.calls.find(([cmd]) => typeof cmd === 'string' && cmd.includes(' respawn-pane '));
+        const sent = await bashArgAfterLocalShell(respawnCall?.[0] as string);
+        expect(sent).toContain('export PATH="$HOME/');
+        expect(sent).not.toContain('local-home-xyz');
+      } finally {
+        nonTestManager.destroy();
+      }
+    });
+
+    it('hands a docker override to bash with $HOME unexpanded', async () => {
+      const NonTestTmuxManager = await importWithTmuxCommandsEnabled();
+      const nonTestManager = new NonTestTmuxManager();
+
+      try {
+        await nonTestManager.createSession({
+          sessionId: 'abc12345-1234-5678-90ab-cdef12345680',
+          workingDir: '/w',
+          mode: 'shell',
+          docker: {
+            hostId: 'h',
+            label: 'L',
+            engine: 'docker',
+            image: 'codeman/agent:base',
+            containerName: 'codeman-case-x',
+            hostWorkspacePath: '/w',
+            containerWorkdir: '/w',
+            commands: { shell: 'echo CONTAINER_HOME=$HOME; exec sleep 30' },
+          } as never,
+        });
+        const launch = [...mockedExecSync.mock.calls, ...vi.mocked(exec).mock.calls]
+          .map(([cmd]) => cmd)
+          .find((cmd) => typeof cmd === 'string' && cmd.includes(' respawn-pane '));
+        const sent = await bashArgAfterLocalShell(launch as string);
+        expect(sent).toContain('docker');
+        expect(sent).toContain('CONTAINER_HOME=$HOME');
+        expect(sent).not.toContain('local-home-xyz');
+      } finally {
+        nonTestManager.destroy();
+      }
+    });
+
     it('changes the global history default on tmux versions that cannot resize panes', async () => {
       const NonTestTmuxManager = await importWithTmuxCommandsEnabled();
       const nonTestManager = new NonTestTmuxManager();