Merge pull request 'docs: public apt setup — one-line source with arch=all (no token, no notices)' (#42) from docs/public-registry into main

Reviewed-on: #42

CHANGELOG.md

@@ -5,6 +5,38 @@ All notable changes to RigDoctor are recorded here. Format follows
 (`MAJOR.MINOR.PATCH`, pre-1.0). `__version__` and `pyproject.toml` must match the git
 release tag (so the auto-updater, D18, can compare versions).
 
+## [0.38.0] - 2026-05-22
+### Added
+- **PCIe link in the Inventory.** Each NVMe drive now shows its negotiated PCIe link next to the
+  model — e.g. `Samsung SSD 980 PRO 1TB (931.5G) · PCIe Gen4 x4` — read from sysfs
+  (`current/max_link_speed` + width). If a drive negotiates below its capability (a slower M.2
+  slot, lane-sharing, or a downtrain) it's flagged: `PCIe Gen3 x4 (capable of Gen4 x4)`. So you
+  can confirm a Gen4 SSD is actually in a Gen4 slot. (SATA disks show no PCIe link.)
+- **System Health flags downtrained NVMe links.** A new check warns when an NVMe drive negotiates
+  fewer PCIe lanes than it supports (almost always motherboard **lane-sharing** — a GPU/second
+  card or another M.2 stealing lanes) and notes speed-only reductions as info (a slower slot or
+  idle ASPM). The GPU is deliberately excluded — NVIDIA drops its PCIe gen/width at idle, so a
+  snapshot would false-alarm.
+
+## [0.37.1] - 2026-05-22
+### Fixed
+- **`rigdoctor update` now uses the right method for how RigDoctor was installed.** It detects
+  apt (`.deb`), pip (venv/`.run`), or source installs (`updates.install_kind()`); only pip
+  installs self-update in place. An apt install no longer fails with "No module named pip" —
+  it (and the GUI Update button) shows `sudo apt update && sudo apt install --only-upgrade
+  rigdoctor`; a source checkout points to `git pull`.
+
+## [0.37.0] - 2026-05-22
+### Added
+- **Version footer** — a footer across the bottom of the window shows `RigDoctor v<version>` in
+  the bottom-right (moved out of the sidebar).
+### Fixed
+- **Pages scroll when content doesn't fit, and the window is no longer pinned to the tallest
+  page's height.** Long pages (Settings, Tuning, …) get a scrollbar when too tall — so controls
+  like Uninstall are always reachable — and the window can now be resized smaller than the screen
+  (min height dropped from "taller than the screen" to ~600px). Pages that manage their own
+  scroll/fill (Dashboard, System Health, Inventory, Share) are unchanged.
+
 ## [0.36.1] - 2026-05-22
 ### Fixed
 - `rigdoctor gui` printed the wrong fix when PySide6 is missing — it suggested the non-existent

README.md

@@ -29,6 +29,16 @@ freeze are usually lost. RigDoctor pulls it together and keeps the evidence.
   or share a live **terminal session** for remote help.
 - **Self-updating** — `apt upgrade`, or the in-app updater.
 
+## Screenshots
+
+| Dashboard | Inventory |
+|---|---|
+| ![Dashboard — live sensors](assets/screenshots/dashboard.png) | ![Inventory — hardware/OS](assets/screenshots/inventory.png) |
+
+**Share** — a read-only or interactive terminal session over the relay, for remote help:
+
+![Share — shared terminal session](assets/screenshots/share.png)
+
 ## Install
 
 ### Debian / Ubuntu — `.deb`
@@ -41,39 +51,19 @@ apt pulls the GUI dependencies (PySide6, pyte) automatically:
 sudo apt install ./rigdoctor_*_all.deb        # CLI only: add --no-install-recommends
 ```
 
-**Or add the apt repository** for `apt install` + automatic updates. The registry is private and
-GPG-signed, so you need a Gitea token with **`read:package`**, the signing key, and the deb822
-source (`read -rsp` keeps the token out of your shell history):
+**Or add the apt repository** for `apt install` + automatic updates (the registry is public and
+GPG-signed — no token needed):
 
 ```bash
-read -rsp 'Gitea read:package token: ' TOKEN; echo
-
-# signing key → dearmored into the keyring (the key endpoint requires the token too)
-sudo install -d -m 0755 /etc/apt/keyrings
-curl -fsSL --user <user>:"$TOKEN" \
-  https://git.jesseyvanofferen.com/api/packages/jessey/debian/repository.key \
-  | sudo gpg --dearmor -o /etc/apt/keyrings/gitea-jessey.gpg
-
-# download credentials, kept out of the sources file
-printf 'machine git.jesseyvanofferen.com login <user> password %s\n' "$TOKEN" \
-  | sudo tee /etc/apt/auth.conf.d/rigdoctor.conf >/dev/null
-sudo chmod 0600 /etc/apt/auth.conf.d/rigdoctor.conf
-
-# the source (modern deb822 format, GPG-verified, all-arch)
-sudo tee /etc/apt/sources.list.d/rigdoctor.sources >/dev/null <<'EOF'
-Types: deb
-URIs: https://git.jesseyvanofferen.com/api/packages/jessey/debian
-Suites: stable
-Components: main
-Architectures: all
-Signed-By: /etc/apt/keyrings/gitea-jessey.gpg
-EOF
-
-sudo apt update && sudo apt install rigdoctor
+sudo curl https://git.jesseyvanofferen.com/api/packages/jessey/debian/repository.key -o /etc/apt/keyrings/gitea-jessey.asc
+echo "deb [arch=all signed-by=/etc/apt/keyrings/gitea-jessey.asc] https://git.jesseyvanofferen.com/api/packages/jessey/debian stable main" | sudo tee /etc/apt/sources.list.d/gitea.list
+sudo apt update
+sudo apt install rigdoctor
 ```
 
-Then `sudo apt upgrade` keeps it current. *(Quick-and-dirty alternative if the registry isn't
-signed: skip the key and use a one-line `deb [arch=all trusted=yes] …/debian stable main` source.)*
+Then `sudo apt upgrade` keeps it current.
+
+Then `sudo apt upgrade` keeps it current.
 
 ### Any distro — self-extracting `.run` (no root)
 

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "rigdoctor"
-version = "0.36.1"
+version = "0.38.0"
 description = "Modular hardware monitoring & crash diagnostics for Linux gamers."
 readme = "README.md"
 requires-python = ">=3.11"

src/rigdoctor/__init__.py

@@ -1,3 +1,3 @@
 """RigDoctor — modular hardware monitoring & crash diagnostics for Linux gamers."""
 
-__version__ = "0.36.1"
+__version__ = "0.38.0"

src/rigdoctor/cli.py

@@ -263,6 +263,10 @@ def cmd_update(args) -> int:
         print("\nWhat's new:\n" + "\n".join("  " + ln for ln in notes.splitlines()) + "\n")
     if args.check:
         return 0
+    kind = updates.install_kind()
+    if kind != "pip":  # apt/source installs aren't pip-updatable — show the right command
+        print(updates.update_hint(kind))
+        return 0
     print(f"Installing {tag}…")
     rc, out = updates.apply_update(tag)
     print(out[-2000:])

src/rigdoctor/core/health.py

@@ -251,6 +251,38 @@ def check_live_temps() -> list[Finding]:
     )]
 
 
+def check_pcie_links() -> list[Finding]:
+    """Flag NVMe drives linked below their PCIe capability — a slower slot or, most often,
+    motherboard lane-sharing where a GPU/second card or another M.2 steals lanes from the slot.
+
+    Width reductions are reliable (reported as warnings); speed-only reductions are info (they can
+    also be normal link power management at idle). The GPU is intentionally not checked here:
+    NVIDIA drops its PCIe gen *and* width at idle, so a point-in-time snapshot is misleading.
+    """
+    from . import inventory
+
+    findings: list[Finding] = []
+    for name, dev in inventory.nvme_controllers():
+        cur_g, cur_w, max_g, max_w = inventory.read_link(dev)
+        if not cur_g or not max_g:
+            continue
+        if max_w and cur_w and cur_w != max_w:  # fewer lanes → almost always lane-sharing
+            findings.append(Finding(
+                WARNING, "PCIe", f"{name} linked at x{cur_w} (supports x{max_w})",
+                f"{name} negotiated PCIe Gen{cur_g} x{cur_w}, but the drive supports "
+                f"Gen{max_g} x{max_w}. Fewer lanes is usually motherboard lane-sharing — a GPU or a "
+                "second card in a PCIe slot, or another populated M.2, can steal lanes from this slot.",
+                "Check your board manual's lane-sharing table; move the drive to a full-x4 "
+                "(often CPU-attached) M.2 slot."))
+        elif cur_g < max_g:  # full width but a lower generation → slower slot or idle ASPM
+            findings.append(Finding(
+                INFO, "PCIe", f"{name} linked at Gen{cur_g} (supports Gen{max_g})",
+                f"{name} negotiated PCIe Gen{cur_g} but supports Gen{max_g}. This can be a slower "
+                "(chipset or older) M.2 slot, or normal link power management (ASPM) at idle.",
+                "If you expect full speed, check the slot and the BIOS PCIe/ASPM settings."))
+    return findings
+
+
 def run_health_checks(include_journal: bool = True) -> list[Finding]:
     """Run all checks and return findings sorted by severity (worst first).
 
@@ -273,5 +305,6 @@ def run_health_checks(include_journal: bool = True) -> list[Finding]:
     else:
         findings += check_smart()
     findings += check_live_temps()
+    findings += check_pcie_links()
     findings.sort(key=lambda f: _ORDER.get(f.severity, 9))
     return findings

src/rigdoctor/core/inventory.py

@@ -9,6 +9,7 @@ from __future__ import annotations
 import json
 import os
 import platform
+import re
 import shutil
 import subprocess
 from dataclasses import dataclass
@@ -123,6 +124,64 @@ def _gpu() -> Section:
     return Section("GPU", [("Device", g) for g in gpus] or [("Device", "unknown")])
 
 
+# PCIe link speed (GT/s) → generation.
+_PCIE_GEN = {"2.5": 1, "5": 2, "5.0": 2, "8": 3, "8.0": 3, "16": 4, "16.0": 4, "32": 5, "32.0": 5}
+
+
+def _gen(speed: str) -> int | None:
+    """Map a sysfs link speed like '16.0 GT/s PCIe' to its PCIe generation (4)."""
+    tok = speed.strip().split()[0] if speed.strip() else ""
+    return _PCIE_GEN.get(tok)
+
+
+def read_link(dev: Path) -> tuple[int | None, str, int | None, str]:
+    """Negotiated/max PCIe link for a PCI device dir: (cur_gen, cur_width, max_gen, max_width).
+
+    Widths are the raw sysfs strings (e.g. '4'); gens are ints (4) or None when unreadable.
+    """
+    def rd(name: str) -> str:
+        try:
+            return (dev / name).read_text().strip()
+        except OSError:
+            return ""
+
+    return (_gen(rd("current_link_speed")), rd("current_link_width"),
+            _gen(rd("max_link_speed")), rd("max_link_width"))
+
+
+def _link_desc(dev: Path) -> str:
+    """Describe a PCI device's negotiated PCIe link, noting if it's below its max.
+
+    e.g. 'PCIe Gen4 x4', or 'PCIe Gen3 x4 (capable of Gen4 x4)' when downtrained / in a
+    slower slot.
+    """
+    cur_g, cur_w, max_g, max_w = read_link(dev)
+    if not cur_g or not cur_w:
+        return ""
+    desc = f"PCIe Gen{cur_g} x{cur_w}"
+    if max_g and (cur_g < max_g or (max_w and cur_w != max_w)):
+        desc += f" (capable of Gen{max_g} x{max_w})"
+    return desc
+
+
+def nvme_controllers() -> list[tuple[str, Path]]:
+    """Each NVMe controller as (name, pci-device-dir), e.g. ('nvme0', /sys/.../device)."""
+    base = Path("/sys/class/nvme")
+    try:
+        entries = [p for p in base.iterdir() if re.fullmatch(r"nvme\d+", p.name)]
+    except OSError:
+        return []
+    return sorted((p.name, p / "device") for p in entries)
+
+
+def _nvme_link(block_name: str) -> str:
+    """PCIe link for an NVMe block device (nvme0n1 → controller nvme0); '' for non-NVMe."""
+    m = re.match(r"(nvme\d+)", block_name)
+    if not m:
+        return ""
+    return _link_desc(Path("/sys/class/nvme") / m.group(1) / "device")
+
+
 def _storage() -> Section:
     items: list[tuple[str, str]] = []
     # TYPE first so MODEL (which can contain spaces) is the trailing field.
@@ -133,7 +192,11 @@ def _storage() -> Section:
             continue
         name, size = parts[1], parts[2]
         model = parts[3] if len(parts) > 3 else ""
-        items.append((name, f"{model} ({size})".strip()))
+        desc = f"{model} ({size})".strip()
+        link = _nvme_link(name)  # NVMe PCIe gen/width (e.g. Gen4 x4), flags downtrains
+        if link:
+            desc += f" · {link}"
+        items.append((name, desc))
     return Section("Storage", items or [("Disks", "unknown")])
 
 

src/rigdoctor/core/updates.py

@@ -8,11 +8,14 @@ state for the UI; `apply_update` performs the no-root self-update.
 
 from __future__ import annotations
 
+import functools
 import json
+import shutil
 import subprocess
 import sys
 import urllib.error
 import urllib.request
+from pathlib import Path
 
 from .. import __version__
 from ..config import load_token
@@ -31,6 +34,50 @@ UP_TO_DATE = "up-to-date"
 AVAILABLE = "available"
 
 
+APT_PACKAGE = "rigdoctor"
+
+
+def _dpkg_owns(path: Path) -> bool:
+    """True if dpkg reports `path` belongs to a package (i.e. an apt/.deb install)."""
+    if not shutil.which("dpkg"):
+        return False
+    try:
+        r = subprocess.run(["dpkg", "-S", str(path)], capture_output=True, text=True, timeout=5)
+    except (subprocess.SubprocessError, OSError):
+        return False
+    return r.returncode == 0 and APT_PACKAGE in r.stdout
+
+
+@functools.lru_cache(maxsize=1)
+def install_kind() -> str:
+    """How RigDoctor was installed: 'apt' (.deb), 'pip' (venv/.run), or 'dev' (source checkout).
+
+    Decides which updater to use: only 'pip' can self-update in place; apt is root/dpkg-managed
+    and source is VCS-managed, so those are guided rather than auto-applied.
+    """
+    pkg = Path(__file__).resolve().parents[1]  # .../rigdoctor
+    if _dpkg_owns(pkg / "__init__.py"):
+        return "apt"
+    if sys.prefix != sys.base_prefix:  # inside a venv → the pip/.run install
+        return "pip"
+    if (pkg.parents[1] / "pyproject.toml").exists():  # repo checkout
+        return "dev"
+    if str(pkg).startswith("/usr/") or "/dist-packages/" in str(pkg):
+        return "apt"  # system-managed but no dpkg record — still don't pip
+    return "pip"
+
+
+def update_hint(kind: str | None = None) -> str:
+    """Human guidance for installs that can't self-update via pip (apt / source)."""
+    kind = kind or install_kind()
+    if kind == "apt":
+        return ("Installed via apt — update with:\n"
+                f"  sudo apt update && sudo apt install --only-upgrade {APT_PACKAGE}")
+    if kind == "dev":
+        return "Running from a source checkout — update with `git pull`."
+    return ""
+
+
 def _parse(version: str) -> tuple[int, ...]:
     return tuple(int(p) for p in version.lstrip("vV").split(".") if p.isdigit())
 
@@ -100,11 +147,16 @@ def list_releases(limit: int = 15, timeout: float = 6.0) -> tuple[list[tuple[str
 
 
 def apply_update(tag: str) -> tuple[int, str]:
-    """Self-update the current (user-local) install to `tag` via authenticated pip.
+    """Update to `tag` using the method matching how RigDoctor was installed.
 
-    Installs `rigdoctor[gui] @ git+https://oauth2:<token>@…/rigdoctor.git@<tag>` into
-    the running environment. Returns (exit_code, output) with the token scrubbed.
+    Only pip/venv installs are upgraded in place (authenticated pip install of
+    `rigdoctor[gui] @ git+https://oauth2:<token>@…/rigdoctor.git@<tag>`). apt and source
+    installs can't be (root/dpkg- or VCS-managed), so they return guidance instead of
+    attempting pip. Returns (exit_code, output) with the token scrubbed.
     """
+    kind = install_kind()
+    if kind != "pip":
+        return (1, update_hint(kind))
     token = load_token()
     if not token:
         return (1, "No update token configured. Run `rigdoctor login`.")

src/rigdoctor/gui/main_window.py

@@ -20,6 +20,7 @@ from PySide6.QtWidgets import (
     QMainWindow,
     QMessageBox,
     QPushButton,
+    QScrollArea,
     QStackedWidget,
     QSystemTrayIcon,
     QTextEdit,
@@ -51,6 +52,10 @@ _NAV = [
     ("App", ["Settings", "Share"]),
 ]
 _PAGES = [name for _section, names in _NAV for name in names]
+# Pages that manage their own scrolling (pinned header + inner scroll) or must fill the
+# viewport (the Share terminal) — these are added to the stack as-is; every other page is
+# wrapped in a QScrollArea so it scrolls when too tall and doesn't pin the window's height.
+_NO_WRAP = {"Dashboard", "System Health", "Inventory", "Share"}
 _ICON = Path(__file__).parent / "assets" / "rigdoctor.svg"
 
 
@@ -68,7 +73,11 @@ class MainWindow(QMainWindow):
 
         central = QWidget()
         self.setCentralWidget(central)
-        layout = QHBoxLayout(central)
+        outer = QVBoxLayout(central)
+        outer.setContentsMargins(0, 0, 0, 0)
+        outer.setSpacing(0)
+        body = QWidget()
+        layout = QHBoxLayout(body)
         layout.setContentsMargins(0, 0, 0, 0)
         layout.setSpacing(0)
 
@@ -100,11 +109,14 @@ class MainWindow(QMainWindow):
             "Share": self.share_page,
         }
         for name in _PAGES:
-            self._stack.addWidget(self._pages[name])
+            page = self._pages[name]
+            self._stack.addWidget(page if name in _NO_WRAP else self._scrollable(page))
         content_layout.addWidget(self._stack)
 
         layout.addWidget(self._build_sidebar())
         layout.addWidget(content, 1)
+        outer.addWidget(body, 1)
+        outer.addWidget(self._build_footer())
 
         self._worker = SamplerWorker(interval=interval)
         self._worker.sampled.connect(self.dashboard.update_sample)
@@ -216,9 +228,6 @@ class MainWindow(QMainWindow):
         v.addStretch(1)
         live = QLabel(f'<span style="color:{ACCENT};">●</span> <span style="color:{MUTED};">Live</span>')
         v.addWidget(live)
-        version = QLabel(f"v{__version__}")
-        version.setObjectName("Muted")
-        v.addWidget(version)
         changelog_btn = QPushButton("Changelog")
         changelog_btn.setObjectName("LinkButton")
         changelog_btn.setCursor(Qt.CursorShape.PointingHandCursor)
@@ -248,6 +257,27 @@ class MainWindow(QMainWindow):
         v.addWidget(self._restart_btn)
         return bar
 
+    def _scrollable(self, page: QWidget) -> QScrollArea:
+        """Wrap a page so it scrolls when taller than the window — and so the window can shrink
+        below the page's natural height instead of being pinned to it."""
+        area = QScrollArea()
+        area.setWidget(page)
+        area.setWidgetResizable(True)
+        area.setFrameShape(QFrame.Shape.NoFrame)
+        area.setHorizontalScrollBarPolicy(Qt.ScrollBarPolicy.ScrollBarAlwaysOff)
+        return area
+
+    def _build_footer(self) -> QFrame:
+        bar = QFrame()
+        bar.setObjectName("Footer")
+        h = QHBoxLayout(bar)
+        h.setContentsMargins(14, 5, 16, 5)
+        h.addStretch(1)
+        version = QLabel(f"RigDoctor v{__version__}")
+        version.setObjectName("Muted")
+        h.addWidget(version)
+        return bar
+
     def _restart(self) -> None:
         gui = os.path.join(os.path.dirname(sys.executable), "rigdoctor-gui")
         if os.path.exists(gui):
@@ -259,6 +289,9 @@ class MainWindow(QMainWindow):
     def _apply_update(self) -> None:
         if not self._latest_tag:
             return
+        if updates.install_kind() != "pip":  # apt/source: can't pip-update — show the command
+            QMessageBox.information(self, "Update RigDoctor", updates.update_hint())
+            return
         box = QMessageBox(self)
         box.setWindowTitle(f"Update to {self._latest_tag}")
         box.setText(f"Update RigDoctor to {self._latest_tag}?")
@@ -424,7 +457,7 @@ class MainWindow(QMainWindow):
             self._update_label.setText("update check unavailable")
         elif state == updates.AVAILABLE:
             self._update_label.setText(f'<span style="color:{GOOD};">{tag} available</span>')
-            self._update_btn.setText(f"Update to {tag}")
+            self._update_btn.setText(f"Update to {tag}" if updates.install_kind() == "pip" else "How to update")
             self._update_btn.setVisible(True)
             if self._alert_monitor.enabled and tag != self._notified_update_tag:
                 self._notified_update_tag = tag  # once per version, not every poll

src/rigdoctor/gui/theme.py

@@ -68,6 +68,8 @@ QMainWindow, #ContentArea, #Page {{ background: {BG}; }}
 QLabel {{ background: transparent; }}
 
 #Sidebar {{ background: {SIDEBAR}; border-right: 1px solid {CARD_BORDER}; }}
+#Footer {{ background: {SIDEBAR}; border-top: 1px solid {CARD_BORDER}; }}
+#Footer QLabel {{ font-size: 11px; }}
 #AppTitle {{ font-size: 17px; font-weight: 800; }}
 #AppSubtitle {{ color: {MUTED}; font-size: 11px; }}
 

tests/test_health.py

@@ -1,8 +1,18 @@
 """Tests for the M4 health report's log scanner (synthetic input)."""
 
 import unittest
+from pathlib import Path
+from unittest import mock
 
-from rigdoctor.core.health import CRITICAL, WARNING, run_health_checks, scan_journal_text
+from rigdoctor.core import health
+from rigdoctor.core.health import (
+    CRITICAL,
+    INFO,
+    WARNING,
+    check_pcie_links,
+    run_health_checks,
+    scan_journal_text,
+)
 
 
 class HealthScanTests(unittest.TestCase):
@@ -42,5 +52,34 @@ class HealthScanTests(unittest.TestCase):
         self.assertEqual(ranks, sorted(ranks))
 
 
+class PcieLinkCheckTests(unittest.TestCase):
+    def _with_link(self, cur_g, cur_w, max_g, max_w):
+        # one fake NVMe controller returning the given link tuple
+        return (mock.patch("rigdoctor.core.inventory.nvme_controllers",
+                           return_value=[("nvme0", Path("/x"))]),
+                mock.patch("rigdoctor.core.inventory.read_link",
+                           return_value=(cur_g, cur_w, max_g, max_w)))
+
+    def test_reduced_width_is_a_warning_about_lane_sharing(self):
+        ctrls, link = self._with_link(4, "2", 4, "4")  # Gen4 x2 but supports x4
+        with ctrls, link:
+            findings = check_pcie_links()
+        self.assertEqual(len(findings), 1)
+        self.assertEqual(findings[0].severity, WARNING)
+        self.assertIn("lane-sharing", findings[0].detail)
+
+    def test_reduced_speed_only_is_info(self):
+        ctrls, link = self._with_link(3, "4", 4, "4")  # Gen3 x4 but supports Gen4
+        with ctrls, link:
+            findings = check_pcie_links()
+        self.assertEqual(len(findings), 1)
+        self.assertEqual(findings[0].severity, INFO)
+
+    def test_full_speed_no_finding(self):
+        ctrls, link = self._with_link(4, "4", 4, "4")
+        with ctrls, link:
+            self.assertEqual(check_pcie_links(), [])
+
+
 if __name__ == "__main__":
     unittest.main()

tests/test_inventory.py

@@ -1,6 +1,8 @@
 """Tests for the M5 system inventory (render + dict round-trip; collect on real system)."""
 
+import tempfile
 import unittest
+from pathlib import Path
 
 from rigdoctor.core import inventory
 from rigdoctor.core.inventory import Section
@@ -26,5 +28,31 @@ class InventoryTests(unittest.TestCase):
         self.assertIn("- **Model:** Test CPU", md)
 
 
+class PcieLinkTests(unittest.TestCase):
+    def test_gen_mapping(self):
+        self.assertEqual(inventory._gen("16.0 GT/s PCIe"), 4)
+        self.assertEqual(inventory._gen("8.0 GT/s PCIe"), 3)
+        self.assertIsNone(inventory._gen(""))
+
+    def _fake_dev(self, cur_s, cur_w, max_s, max_w) -> Path:
+        d = Path(tempfile.mkdtemp())
+        (d / "current_link_speed").write_text(cur_s)
+        (d / "current_link_width").write_text(cur_w)
+        (d / "max_link_speed").write_text(max_s)
+        (d / "max_link_width").write_text(max_w)
+        return d
+
+    def test_link_at_full_speed(self):
+        dev = self._fake_dev("16.0 GT/s PCIe", "4", "16.0 GT/s PCIe", "4")
+        self.assertEqual(inventory._link_desc(dev), "PCIe Gen4 x4")
+
+    def test_link_downtrained_flags_capability(self):
+        dev = self._fake_dev("8.0 GT/s PCIe", "4", "16.0 GT/s PCIe", "4")
+        self.assertEqual(inventory._link_desc(dev), "PCIe Gen3 x4 (capable of Gen4 x4)")
+
+    def test_non_nvme_has_no_link(self):
+        self.assertEqual(inventory._nvme_link("sda"), "")
+
+
 if __name__ == "__main__":
     unittest.main()

tests/test_updates.py

@@ -0,0 +1,64 @@
+"""Tests for the M13 updater: install detection + routing the update to the right method."""
+
+import unittest
+from unittest import mock
+
+from rigdoctor.core import updates
+
+
+class InstallKindTests(unittest.TestCase):
+    def setUp(self):
+        updates.install_kind.cache_clear()
+
+    def tearDown(self):
+        updates.install_kind.cache_clear()
+
+    def test_apt_when_dpkg_owns_the_package(self):
+        with mock.patch.object(updates, "_dpkg_owns", return_value=True):
+            self.assertEqual(updates.install_kind(), "apt")
+
+    def test_pip_when_running_in_a_venv(self):
+        with mock.patch.object(updates, "_dpkg_owns", return_value=False), \
+             mock.patch.object(updates.sys, "prefix", "/opt/venv"), \
+             mock.patch.object(updates.sys, "base_prefix", "/usr"):
+            self.assertEqual(updates.install_kind(), "pip")
+
+
+class ApplyUpdateRoutingTests(unittest.TestCase):
+    def test_apt_returns_guidance_and_never_runs_pip(self):
+        with mock.patch.object(updates, "install_kind", return_value="apt"), \
+             mock.patch("subprocess.run") as run:
+            rc, out = updates.apply_update("v9.9.9")
+        self.assertEqual(rc, 1)
+        self.assertIn("apt install --only-upgrade", out)
+        run.assert_not_called()
+
+    def test_dev_returns_guidance_and_never_runs_pip(self):
+        with mock.patch.object(updates, "install_kind", return_value="dev"), \
+             mock.patch("subprocess.run") as run:
+            rc, out = updates.apply_update("v9.9.9")
+        self.assertIn("git pull", out)
+        run.assert_not_called()
+
+    def test_pip_install_runs_pip(self):
+        proc = mock.Mock(returncode=0, stdout="Successfully installed", stderr="")
+        with mock.patch.object(updates, "install_kind", return_value="pip"), \
+             mock.patch.object(updates, "load_token", return_value="TOK"), \
+             mock.patch("subprocess.run", return_value=proc) as run:
+            rc, _out = updates.apply_update("v1.2.3")
+        self.assertEqual(rc, 0)
+        cmd = run.call_args[0][0]
+        self.assertIn("pip", cmd)
+        self.assertIn("install", cmd)
+
+
+class UpdateHintTests(unittest.TestCase):
+    def test_apt_hint_names_the_apt_command(self):
+        self.assertIn("apt install --only-upgrade rigdoctor", updates.update_hint("apt"))
+
+    def test_dev_hint_says_git_pull(self):
+        self.assertIn("git pull", updates.update_hint("dev"))
+
+
+if __name__ == "__main__":
+    unittest.main()