NousResearch · teknium1 · Apr 28, 2026 · Apr 28, 2026 · Apr 28, 2026 · Apr 28, 2026
diff --git a/scripts/install.sh b/scripts/install.sh
@@ -729,9 +729,12 @@ install_system_packages() {
                         return 0
                     fi
                 fi
-            elif [ -e /dev/tty ]; then
+            elif (: </dev/tty) 2>/dev/null; then
                 # Non-interactive (e.g. curl | bash) but a terminal is available.
                 # Read the prompt from /dev/tty (same approach the setup wizard uses).
+                # Probe by actually opening /dev/tty: a bare existence test passes
+                # in Docker builds where the device node is in the mount namespace
+                # but opening fails with ENXIO. See #16746.
                 echo ""
                 log_info "sudo is needed ONLY to install optional system packages (${pkgs[*]}) via your package manager."
                 log_info "Hermes Agent itself does not require or retain root access."
@@ -1330,7 +1333,12 @@ run_setup_wizard() {
     # The setup wizard reads from /dev/tty, so it works even when the
     # install script itself is piped (curl | bash). Only skip if no
     # terminal is available at all (e.g. Docker build, CI).
-    if ! [ -e /dev/tty ]; then
+    #
+    # Probe by actually opening /dev/tty: a bare existence test passes
+    # in Docker builds where the device node is in the mount namespace
+    # but opening fails with ENXIO, so the wizard would proceed and
+    # then crash on `< /dev/tty` below.
+    if ! (: </dev/tty) 2>/dev/null; then
         log_info "Setup wizard skipped (no terminal available). Run 'hermes setup' after install."
         return 0
     fi
@@ -1392,7 +1400,10 @@ maybe_start_gateway() {
         fi
     fi
 
-    if ! [ -e /dev/tty ]; then
+    # Probe by actually opening /dev/tty: a bare existence test passes
+    # in Docker builds where the device node is in the mount namespace
+    # but opening fails with ENXIO. See #16746.
+    if ! (: </dev/tty) 2>/dev/null; then
         log_info "Gateway setup skipped (no terminal available). Run 'hermes gateway install' later."
         return 0
     fi

diff --git a/tests/test_install_sh_setup_wizard_tty_probe.py b/tests/test_install_sh_setup_wizard_tty_probe.py
@@ -0,0 +1,91 @@
+"""Regression for #16746: install.sh /dev/tty gates must actually open /dev/tty.
+
+In a Docker build, ``/dev/tty`` exists as a device node (so a bare ``-e``
+existence test returns true) but opening it fails with ``ENXIO: No such
+device or address``. Under the old gates the script proceeded past the "no
+terminal available" skip and then crashed on the ``< /dev/tty`` redirect a
+few lines later, aborting the entire image build. The fix replaces every
+existence-based check that guards a subsequent ``< /dev/tty`` redirect with
+an open-based probe so the skip kicks in correctly.
+
+This module covers all three affected functions: ``run_setup_wizard()``
+(the reproducer in #16746), ``install_system_packages()`` (the apt sudo
+prompt fallback), and ``maybe_start_gateway()`` (the gateway-install gate).
+"""
+
+from __future__ import annotations
+
+import re
+from pathlib import Path
+
+import pytest
+
+REPO_ROOT = Path(__file__).resolve().parent.parent
+INSTALL_SH = REPO_ROOT / "scripts" / "install.sh"
+
+# Every function in scripts/install.sh that previously gated on a bare
+# ``[ -e /dev/tty ]`` check before redirecting stdin from ``/dev/tty``.
+GATED_FUNCTIONS = ("run_setup_wizard", "install_system_packages", "maybe_start_gateway")
+
+
+def _extract_function_body(name: str) -> str:
+    """Return the body of ``<name>()`` as a single string.
+
+    Anchored to ``<name>()`` and a top-of-line ``}`` so the helper keeps
+    working if neighbouring functions are renamed.
+    """
+    text = INSTALL_SH.read_text()
+    match = re.search(
+        rf"^{re.escape(name)}\(\)\s*\{{\s*\n(?P<body>.*?)^\}}",
+        text,
+        re.MULTILINE | re.DOTALL,
+    )
+    assert match is not None, f"{name}() not found in scripts/install.sh"
+    return match["body"]
+
+
+@pytest.mark.parametrize("fn_name", GATED_FUNCTIONS)
+def test_tty_gate_does_not_use_existence_only_check(fn_name: str) -> None:
+    """The bare ``-e`` test is the bug — no spelling of it should remain."""
+    body = _extract_function_body(fn_name)
+    # Cover ``[ -e /dev/tty ]``, ``[ -e "/dev/tty" ]``, ``test -e /dev/tty``
+    # and friends, with arbitrary surrounding whitespace.
+    pattern = re.compile(
+        r"""(
+            \[\s*-e\s+["']?/dev/tty["']?\s*\]
+            |
+            \btest\s+-e\s+["']?/dev/tty["']?
+        )""",
+        re.VERBOSE,
+    )
+    match = pattern.search(body)
+    assert match is None, (
+        f"{fn_name} contains an existence-only check on /dev/tty "
+        f"({match.group(0)!r}). Bare `-e` tests pass in Docker builds "
+        "where the device node is in the mount namespace but cannot be "
+        "opened (ENXIO). Use an open-based probe (e.g. "
+        "`(: </dev/tty) 2>/dev/null` or `exec 3</dev/tty`) so the skip "
+        "kicks in before the function tries to read from /dev/tty. "
+        "See #16746."
+    )
+
+
+@pytest.mark.parametrize("fn_name", GATED_FUNCTIONS)
+def test_tty_gate_uses_open_based_probe(fn_name: str) -> None:
+    """The gate must actually attempt to open ``/dev/tty``.
+
+    Any ``if``/``if !``/``elif`` whose condition opens ``/dev/tty`` for
+    input counts: ``(: </dev/tty)``, ``exec 3</dev/tty``,
+    ``{ exec 3</dev/tty; }``, etc. Asserting the higher-level invariant
+    rather than a specific spelling so equivalent refactors stay green.
+    """
+    body = _extract_function_body(fn_name)
+    gate = re.compile(
+        r"^\s*(?:if|elif)\s+!?\s*[^\n]*<\s*/dev/tty[^\n]*;\s*then",
+        re.MULTILINE,
+    )
+    assert gate.search(body), (
+        f"{fn_name} must gate on an open-based probe of /dev/tty "
+        "(an `if`/`if !`/`elif` whose test redirects stdin from /dev/tty), "
+        "not a mere existence check. See #16746."
+    )