fix(installer): keep fallback installs stable-only

scripts/install.sh

@@ -47,17 +47,15 @@ elif [ -f "$(dirname "$0")/../pyproject.toml" ] && grep -q "name = \"ouroboros-a
   IS_LOCAL=true
 fi
 
-# Auto-detect: if a stable release exists on PyPI, use it. Otherwise allow pre-release.
-# PyPI /json info.version returns latest stable only.
-# If python3 is unavailable for JSON parsing, PRE_FLAG stays "yes" which is safe:
-# --pre/--prerelease=allow still installs stable versions when they're the latest.
-PRE_FLAG="yes"
+# Auto-detect: if PyPI's latest published version is a pre-release, allow
+# pre-releases. On lookup/parsing failure, stay stable-only.
+PRE_FLAG=""
 if [ "$IS_LOCAL" = false ] && command -v curl &>/dev/null; then
-  STABLE=$(curl -fsSL "https://pypi.org/pypi/${PACKAGE_NAME}/json" 2>/dev/null \
+  LATEST=$(curl -fsSL "https://pypi.org/pypi/${PACKAGE_NAME}/json" 2>/dev/null \
     | python3 -c "import sys,json; print(json.load(sys.stdin)['info']['version'])" 2>/dev/null || true)
-  if [ -n "$STABLE" ]; then
-    if ! echo "$STABLE" | grep -qE '(a|b|rc|dev)'; then
-      PRE_FLAG=""
+  if [ -n "$LATEST" ]; then
+    if echo "$LATEST" | grep -qE '(a|b|rc|dev)'; then
+      PRE_FLAG="yes"
     fi
   fi
 fi

tests/unit/scripts/test_install_runtime_selection.py

@@ -18,6 +18,7 @@ def _write_executable(path: Path, content: str) -> None:
 def _run_installer(
     tmp_path: Path,
     *,
+    local_repo: bool = True,
     env: dict[str, str] | None = None,
     fake_commands: dict[str, str] | None = None,
 ) -> subprocess.CompletedProcess[str]:
@@ -47,6 +48,14 @@ def _run_installer(
         for name, content in fake_commands.items():
             _write_executable(bin_dir / name, content)
 
+    install_sh = INSTALL_SH
+    cwd = REPO_ROOT
+    if not local_repo:
+        install_sh = tmp_path / "install.sh"
+        install_sh.write_text(INSTALL_SH.read_text(encoding="utf-8"), encoding="utf-8")
+        install_sh.chmod(0o755)
+        cwd = tmp_path
+
     run_env = os.environ.copy()
     run_env.update(
         {
@@ -58,8 +67,8 @@ def _run_installer(
         run_env.update(env)
 
     return subprocess.run(
-        ["bash", str(INSTALL_SH)],
-        cwd=REPO_ROOT,
+        ["bash", str(install_sh)],
+        cwd=cwd,
         env=run_env,
         text=True,
         capture_output=True,
@@ -89,7 +98,7 @@ def test_preserves_opencode_backend_from_existing_config(tmp_path: Path) -> None
     assert "Runtime: opencode (preserved from" in result.stdout
     assert "Installing . ..." in result.stdout
     assert (tmp_path / "calls.log").read_text(encoding="utf-8").splitlines() == [
-        "uv tool install --upgrade --python >=3.12 . --prerelease=allow",
+        "uv tool install --upgrade --python >=3.12 .",
         "ouroboros setup --runtime opencode --non-interactive",
     ]
 
@@ -105,12 +114,26 @@ def test_explicit_claude_installs_mcp_and_claude_extras(tmp_path: Path) -> None:
     calls = (tmp_path / "calls.log").read_text(encoding="utf-8")
     assert "Runtime: claude (from --runtime / OUROBOROS_INSTALL_RUNTIME)" in result.stdout
     assert (
-        "uv tool install --upgrade --python >=3.12 . --prerelease=allow --with mcp>=1.26.0,<2.0.0 --with claude-agent-sdk>=0.1.0,<1.0.0 --with anthropic>=0.52.0,<1.0.0"
+        "uv tool install --upgrade --python >=3.12 . --with mcp>=1.26.0,<2.0.0 --with claude-agent-sdk>=0.1.0,<1.0.0 --with anthropic>=0.52.0,<1.0.0"
         in calls
     )
     assert "ouroboros setup --runtime claude --non-interactive" in calls
 
 
+def test_pypi_lookup_failure_stays_stable_only_for_remote_install(tmp_path: Path) -> None:
+    result = _run_installer(
+        tmp_path,
+        local_repo=False,
+        env={"OUROBOROS_INSTALL_RUNTIME": "codex"},
+        fake_commands={"curl": "#!/bin/sh\nexit 22\n"},
+    )
+
+    assert result.returncode == 0, result.stderr
+    calls = (tmp_path / "calls.log").read_text(encoding="utf-8")
+    assert "uv tool install --upgrade --python >=3.12 ouroboros-ai" in calls
+    assert "--prerelease=allow" not in calls
+
+
 # ---------------------------------------------------------------------------
 # pyproject ↔ install.sh `[all]` extras parity
 # ---------------------------------------------------------------------------