i3blocks: XDG_RUNTIME_DIR falls back to /run/user/$UID, not /tmp

A session started while logind was off the system bus had no
XDG_RUNTIME_DIR, so the gaming and shutdown blocks looked for
daily-limits' cache in /tmp and showed '⏱? no data'.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DHsV8jzhhX162EcxxEXbca

docs/superpowers/contracts/i3blocks-runtime-dir-fallback-2026-10-12.json

@@ -0,0 +1,14 @@
+{
+  "title": "i3blocks: XDG_RUNTIME_DIR falls back to /run/user/$UID",
+  "objective": "The gaming, shutdown and screen-locker blocks read daily-limits' cache from /run/user/$UID when the X session has no XDG_RUNTIME_DIR, instead of looking in /tmp and showing '⏱? no data'.",
+  "acceptance_criteria": [
+    "With XDG_RUNTIME_DIR unset, gaming_budget.sh and shutdown_countdown.sh render the live cache (time left, unearned earners)",
+    "No i3blocks script falls back to /tmp for XDG_RUNTIME_DIR (checked in test_i3blocks_efficiency.sh)",
+    "test_i3blocks_{efficiency,shutdown_hint,gaming_budget}.sh pass"
+  ],
+  "out_of_scope": [
+    "Reconnecting systemd-logind to the system bus (needs a logind restart and relogin)",
+    "Finding what re-parses systemd units every ~6 s"
+  ],
+  "verifier": "bash linux_configuration/tests/test_i3blocks_efficiency.sh && bash linux_configuration/tests/test_i3blocks_shutdown_hint.sh && bash linux_configuration/tests/test_i3blocks_gaming_budget.sh"
+}

docs/superpowers/evidence/i3blocks-runtime-dir-fallback-2026-10-12.json

@@ -0,0 +1,31 @@
+{
+  "intent": "i3blocks gaming/shutdown/screen-locker blocks find daily-limits' cache even when the X session started without XDG_RUNTIME_DIR.",
+  "scope": [
+    "linux_configuration/i3blocks/{gaming_budget,shutdown_countdown,screen_locker}.sh",
+    "linux_configuration/tests/test_i3blocks_efficiency.sh",
+    "Non-goal: repairing logind's lost bus connection (needs a logind restart/relogin)"
+  ],
+  "changes": [
+    "XDG_RUNTIME_DIR fallback changed from /tmp to /run/user/$UID (bash builtin, no fork)",
+    "Regression check: no i3blocks script may fall back to /tmp for XDG_RUNTIME_DIR"
+  ],
+  "verification": [
+    {
+      "command": "env -u XDG_RUNTIME_DIR bash linux_configuration/i3blocks/gaming_budget.sh (and shutdown_countdown.sh)",
+      "result": "pass",
+      "evidence": "🎮 5h00 left · 0h00/5h00 +🧩1h +📖1h +⚙1h / ⏻ 20:40 +🧩50m +📖30m +⚙1h →max 23:00; live bar confirmed by user"
+    },
+    {
+      "command": "bash linux_configuration/tests/test_i3blocks_{efficiency,shutdown_hint,gaming_budget}.sh",
+      "result": "pass",
+      "evidence": "all three suites exit 0"
+    }
+  ],
+  "risks": [
+    "A non-systemd login would still have no /run/user/$UID; the blocks then show the existing missing-cache state"
+  ],
+  "rollback": [
+    "git revert this commit",
+    "Re-run the three i3blocks test suites"
+  ]
+}

linux_configuration/i3blocks/gaming_budget.sh

@@ -14,8 +14,8 @@
 
 set -euo pipefail
 
-readonly LIMITS_CACHE="${DAILY_LIMITS_CACHE:-${XDG_RUNTIME_DIR:-/tmp}/daily-limits.json}"
-readonly RENDER_CACHE="${DAILY_LIMITS_RENDER_CACHE:-${XDG_RUNTIME_DIR:-/tmp}/i3blocks-gaming-budget.render}"
+readonly LIMITS_CACHE="${DAILY_LIMITS_CACHE:-${XDG_RUNTIME_DIR:-/run/user/$UID}/daily-limits.json}"
+readonly RENDER_CACHE="${DAILY_LIMITS_RENDER_CACHE:-${XDG_RUNTIME_DIR:-/run/user/$UID}/i3blocks-gaming-budget.render}"
 readonly STALE_AFTER_SECONDS=180
 
 # Dracula-ish palette, matching screen_locker.sh.

linux_configuration/i3blocks/screen_locker.sh

@@ -16,7 +16,7 @@ set -euo pipefail
 readonly API='http://127.0.0.1:8770/api/status'
 readonly HEALTH='http://127.0.0.1:8770/api/health'
 readonly UI='http://127.0.0.1:8770/'
-readonly CACHE="${XDG_RUNTIME_DIR:-/tmp}/i3blocks-screen-locker.cache"
+readonly CACHE="${XDG_RUNTIME_DIR:-/run/user/$UID}/i3blocks-screen-locker.cache"
 
 # Dracula-ish palette, matching the other blocks in this bar.
 readonly RED='#FF5555'

linux_configuration/i3blocks/shutdown_countdown.sh

@@ -16,8 +16,8 @@ set -euo pipefail
 SHUTDOWN_CONFIG=${SHUTDOWN_CONFIG:-/etc/shutdown-schedule.conf}
 SKIP_DATES_FILE=${SKIP_DATES_FILE:-/etc/shutdown-skip-dates}
 OVERRIDES_FILE=${OVERRIDES_FILE:-/etc/shutdown-schedule-overrides.conf}
-LIMITS_CACHE=${DAILY_LIMITS_CACHE:-${XDG_RUNTIME_DIR:-/tmp}/daily-limits.json}
-RENDER_CACHE=${DAILY_LIMITS_RENDER_CACHE:-${XDG_RUNTIME_DIR:-/tmp}/i3blocks-shutdown.render}
+LIMITS_CACHE=${DAILY_LIMITS_CACHE:-${XDG_RUNTIME_DIR:-/run/user/$UID}/daily-limits.json}
+RENDER_CACHE=${DAILY_LIMITS_RENDER_CACHE:-${XDG_RUNTIME_DIR:-/run/user/$UID}/i3blocks-shutdown.render}
 readonly STALE_AFTER_SECONDS=180
 
 # Left-click opens the popup, by path: i3blocks' PATH has no ~/.local/bin.

linux_configuration/tests/test_i3blocks_efficiency.sh

@@ -235,4 +235,11 @@ shutdown_minutes_output=$(TZ=UTC NOW_EPOCH="$(epoch_utc '2026-05-01 18:31:00')"
 assert_equals '⏻ SHUTDOWN' "$(printf '%s\n' "$shutdown_minutes_output" | sed -n '1p')" \
 	'shutdown countdown should be due once the shutdown minute has passed'
 
+# A session started while logind is off the bus has no XDG_RUNTIME_DIR; a /tmp
+# fallback then misses daily-limits' cache in /run/user/$UID (2026-10-12).
+if grep -n 'XDG_RUNTIME_DIR:-/tmp' "$I3BLOCKS_DIR"/*.sh; then
+	printf 'FAIL: XDG_RUNTIME_DIR must fall back to /run/user/<uid>, not /tmp\n' >&2
+	exit 1
+fi
+
 printf 'All i3blocks efficiency regression tests passed.\n'