apt: surface phased-update holdbacks in Upgrade conflicts (fixes #9 feedback)

CHANGELOG.md

@@ -31,6 +31,15 @@ follow [SemVer](https://semver.org/).
   cask also clears the Gatekeeper quarantine attribute, which these
   un-notarized binaries would otherwise trip over on first run.
 
+### Fixed
+
+- **Upgrade conflicts (`X`, apt)** now also reports packages held back by
+  Ubuntu's phased-update rollout, not just dependency-based holdbacks:
+  these showed up as plain "upgradable" with no indication that "upgrade
+  all" (`U`, dist-upgrade) won't actually touch them until the rollout
+  reaches this machine (see
+  [#9](https://github.com/padovanl/pkgtui/issues/9)).
+
 ### Changed
 
 - The `P` screen manages **third-party sources generally**, not just apt

README.md

@@ -134,7 +134,10 @@ own:
   something else first — distinct from an explicit hold, which already
   has its own `◆` marker. "Upgrade all" (`U`) already resolves most of
   these on its own (it uses `dist-upgrade`); this is what tells you
-  *which* ones and *why*.
+  *which* ones and *why*. Also surfaces packages Ubuntu's phased update
+  rollout is holding back from this machine, which show up as plainly
+  "upgradable" everywhere else but that neither a plain upgrade nor
+  `dist-upgrade` will actually touch until the rollout reaches you.
 - **Action log (`L`)**: every privileged action run this session, all
   backends together, with a timestamp and success/failure — a running
   record of what you actually did, without digging through shell
@@ -265,7 +268,7 @@ pkgtui
 | `O`         | Backend overlap view: packages installed more than once, stale snaps |
 | `V`         | Install a specific version of the selected package / downgrade (apt); revert to the previous revision (snap) |
 | `M`         | Metrics dashboard: installed packages ranked by disk usage |
-| `X`         | Upgrade conflicts: packages a plain upgrade would keep back (apt) |
+| `X`         | Upgrade conflicts: packages a plain upgrade would keep back, or Ubuntu's phased rollout is holding back (apt) |
 | `L`         | Action log: what's run this session, and whether it succeeded |
 | `y` / `n`   | Confirm / cancel an action                  |
 | `esc`       | Go back                                     |

docs/index.html

@@ -544,7 +544,7 @@ <h2>Beyond wrapping the package managers</h2>
         <div class="feature-window">
           <div class="term-titlebar"><span>Upgrade conflicts</span><span class="chip"><span class="k">X</span></span></div>
           <div class="feature-window-body">
-            <p>Packages a conservative apt-get upgrade would leave behind because it needs to install or remove something else first — distinct from an explicit hold. "Upgrade all" already resolves most of these; this shows which, and why.</p>
+            <p>Packages a conservative apt-get upgrade would leave behind because it needs to install or remove something else first — distinct from an explicit hold. "Upgrade all" already resolves most of these; this shows which, and why. Also catches packages Ubuntu's phased update rollout is holding back, which neither a plain upgrade nor "Upgrade all" will touch until the rollout reaches this machine.</p>
           </div>
         </div>
 
@@ -649,7 +649,7 @@ <h2>Every key, one dashboard</h2>
           <tr><td><kbd>O</kbd></td><td>Backend overlap: packages installed more than once, stale snaps</td></tr>
           <tr><td><kbd>V</kbd></td><td>Install a specific version / downgrade (apt); revert (snap)</td></tr>
           <tr><td><kbd>M</kbd></td><td>Metrics dashboard: installed packages ranked by disk usage</td></tr>
-          <tr><td><kbd>X</kbd></td><td>Upgrade conflicts: packages a plain upgrade would keep back (apt)</td></tr>
+          <tr><td><kbd>X</kbd></td><td>Upgrade conflicts: packages a plain upgrade would keep back, or Ubuntu's phased rollout is holding back (apt)</td></tr>
           <tr><td><kbd>L</kbd></td><td>Action log: what's run this session, and whether it succeeded</td></tr>
           <tr><td><kbd>y</kbd> / <kbd>n</kbd></td><td>Confirm / cancel a pending action</td></tr>
           <tr><td><kbd>esc</kbd></td><td>Go back</td></tr>

internal/apt/apt.go

@@ -287,14 +287,11 @@ func (m *Manager) InstallVersionCmd(name, version string) []string {
 	return pkg.MaybeSudo([]string{"apt-get", "install", "-y", name + "=" + version})
 }
 
-// parseKeptBackOutput extracts package names from "apt-get upgrade -s"'s
-// "The following packages have been kept back:" section: packages with an
-// upgrade available that a conservative upgrade won't perform because it
-// would need to install or remove something else first. The section is a
-// run of "  "-indented lines (names wrapped across several lines for a
-// long list), terminated by the first line that isn't indented that way.
-func parseKeptBackOutput(out string) []string {
-	const marker = "The following packages have been kept back:"
+// parseNamesUnderMarker extracts the names listed under a section header
+// line starting with marker, as "apt-get upgrade -s" prints them: a run of
+// "  "-indented lines (names wrapped across several lines for a long
+// list), terminated by the first line that isn't indented that way.
+func parseNamesUnderMarker(out, marker string) []string {
 	var names []string
 	inSection := false
 	for _, line := range strings.Split(out, "\n") {
@@ -313,17 +310,41 @@ func parseKeptBackOutput(out string) []string {
 	return names
 }
 
-// UpgradeConflicts reports packages a conservative "apt-get upgrade" would
-// leave behind (as opposed to "upgrade all" in this UI, which already uses
-// dist-upgrade and resolves most of these on its own — see UpgradeCmd).
-// Implements pkg.ConflictReporter.
+// parseKeptBackOutput extracts package names from "apt-get upgrade -s"'s
+// "The following packages have been kept back:" section: packages with an
+// upgrade available that a conservative upgrade won't perform because it
+// would need to install or remove something else first.
+func parseKeptBackOutput(out string) []string {
+	return parseNamesUnderMarker(out, "The following packages have been kept back:")
+}
+
+// parsePhasedOutput extracts package names from "apt-get upgrade -s"'s
+// "The following upgrades have been deferred due to phasing:" section
+// (apt >= 21.04, ubiquitous since Ubuntu 24.04): packages held back by
+// Ubuntu's gradual update rollout rather than a dependency conflict. This
+// is orthogonal to dist-upgrade vs. plain upgrade — "upgrade all" (which
+// uses dist-upgrade, see UpgradeCmd) does not bypass phasing either, so
+// these would otherwise show as plainly "upgradable" (apt list
+// --upgradable lists them regardless of phasing) without ever actually
+// being picked up by "upgrade all".
+func parsePhasedOutput(out string) []string {
+	return parseNamesUnderMarker(out, "The following upgrades have been deferred due to phasing:")
+}
+
+// UpgradeConflicts reports packages "upgrade all" (dist-upgrade) won't
+// actually touch despite showing up as upgradable elsewhere: a
+// conservative "apt-get upgrade" simulation surfaces both dependency-based
+// holdbacks (which dist-upgrade resolves on its own — see UpgradeCmd) and
+// phased-rollout holdbacks (which it doesn't). Implements
+// pkg.ConflictReporter.
 func (m *Manager) UpgradeConflicts() ([]pkg.UpgradeConflict, error) {
 	out, err := exec.Command("apt-get", "upgrade", "-s").Output()
 	if err != nil {
 		return nil, fmt.Errorf("apt-get upgrade -s: %w", err)
 	}
-	names := parseKeptBackOutput(string(out))
-	if len(names) == 0 {
+	keptBack := parseKeptBackOutput(string(out))
+	phased := parsePhasedOutput(string(out))
+	if len(keptBack) == 0 && len(phased) == 0 {
 		return nil, nil
 	}
 	held := map[string]bool{}
@@ -332,14 +353,17 @@ func (m *Manager) UpgradeConflicts() ([]pkg.UpgradeConflict, error) {
 			held[name] = e.Held
 		}
 	}
-	items := make([]pkg.UpgradeConflict, 0, len(names))
-	for _, name := range names {
+	items := make([]pkg.UpgradeConflict, 0, len(keptBack)+len(phased))
+	for _, name := range keptBack {
 		reason := "needs a dependency change (install/remove something else) a plain upgrade won't perform on its own"
 		if held[name] {
 			reason = "held (apt-mark hold)"
 		}
 		items = append(items, pkg.UpgradeConflict{Name: name, Reason: reason})
 	}
+	for _, name := range phased {
+		items = append(items, pkg.UpgradeConflict{Name: name, Reason: "held back by Ubuntu's phased rollout, not yet offered to this machine (upgrading it by name bypasses phasing)"})
+	}
 	return items, nil
 }
 

internal/apt/apt_test.go

@@ -301,6 +301,29 @@ func TestParseKeptBackOutputNothingKeptBack(t *testing.T) {
 	}
 }
 
+func TestParsePhasedOutput(t *testing.T) {
+	out := `Reading package lists...
+Building dependency tree...
+Reading state information...
+Calculating upgrade...
+The following upgrades have been deferred due to phasing:
+  libglapi-mesa libgl1-mesa-dri
+0 upgraded, 0 newly installed, 0 to remove and 2 not upgraded.
+`
+	got := parsePhasedOutput(out)
+	want := []string{"libglapi-mesa", "libgl1-mesa-dri"}
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("parsePhasedOutput() = %v, want %v", got, want)
+	}
+}
+
+func TestParsePhasedOutputNothingPhased(t *testing.T) {
+	out := "Reading package lists...\nBuilding dependency tree...\n0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.\n"
+	if got := parsePhasedOutput(out); len(got) != 0 {
+		t.Errorf("parsePhasedOutput() = %v, want empty", got)
+	}
+}
+
 func TestParseUnattendedUpgradesLogNoMatches(t *testing.T) {
 	ts, pkgs := parseUnattendedUpgradesLog("nothing relevant here\n")
 	if ts != "" || pkgs != nil {