diff --git a/skills/continuous-learning-v2/agents/observer-loop.sh b/skills/continuous-learning-v2/agents/observer-loop.sh
index 698cd8b68..f75365920 100755
--- a/skills/continuous-learning-v2/agents/observer-loop.sh
+++ b/skills/continuous-learning-v2/agents/observer-loop.sh
@@ -248,13 +248,16 @@ PROMPT
   # Pass prompt via -p flag instead of stdin redirect for Windows compatibility (#842).
   # prompt_content is already loaded in-memory so this no longer depends on the
   # mktemp absolute path continuing to resolve after cwd changes (#1296).
+  # stdin is explicitly closed with </dev/null: on Git Bash/MSYS2 the backgrounded
+  # child otherwise inherits an open stdin, and claude waits on it, warns
+  # "no stdin data received", and exits 1 before reading the analysis file (#2452).
   # Model is configurable via ECC_OBSERVER_MODEL (defaults to haiku for cost efficiency);
   # e.g. ECC_OBSERVER_MODEL=opus for higher-quality instinct extraction. Heavier models are
   # slower — consider raising ECC_OBSERVER_TIMEOUT_SECONDS (default 120s) so the watchdog
   # doesn't kill the analysis mid-run.
   ECC_SKIP_OBSERVE=1 ECC_HOOK_PROFILE=minimal claude --model "${ECC_OBSERVER_MODEL:-haiku}" --max-turns "$max_turns" --print \
     --allowedTools "Read,Write" \
-    -p "$prompt_content" >> "$LOG_FILE" 2>&1 &
+    -p "$prompt_content" < /dev/null >> "$LOG_FILE" 2>&1 &
   claude_pid=$!
 
   (
diff --git a/tests/hooks/hooks.test.js b/tests/hooks/hooks.test.js
index 2830fbed3..82724226a 100644
--- a/tests/hooks/hooks.test.js
+++ b/tests/hooks/hooks.test.js
@@ -3175,6 +3175,40 @@ async function runTests() {
     passed++;
   else failed++;
 
+  if (
+    test('observer scripts only call homunculus resolvers the shared lib defines (#2452)', () => {
+      const skillRoot = path.join(__dirname, '..', '..', 'skills', 'continuous-learning-v2');
+      const libSource = fs.readFileSync(path.join(skillRoot, 'scripts', 'lib', 'homunculus-dir.sh'), 'utf8');
+      const definedResolvers = new Set([...libSource.matchAll(/^([A-Za-z_][A-Za-z0-9_]*_resolve_homunculus_dir)\(\)/gm)].map((m) => m[1]));
+      assert.ok(definedResolvers.size > 0, 'homunculus-dir.sh should define a homunculus resolver function');
+
+      const callers = [
+        ['agents', 'start-observer.sh'],
+        ['hooks', 'observe.sh'],
+        ['scripts', 'detect-project.sh'],
+        ['scripts', 'migrate-homunculus.sh']
+      ];
+      for (const rel of callers) {
+        const callerSource = fs.readFileSync(path.join(skillRoot, ...rel), 'utf8');
+        for (const match of callerSource.matchAll(/([A-Za-z_][A-Za-z0-9_]*_resolve_homunculus_dir)\b/g)) {
+          assert.ok(definedResolvers.has(match[1]), `${rel.join('/')} calls ${match[1]}, which homunculus-dir.sh does not define (stale name breaks daemon boot under set -e)`);
+        }
+      }
+    })
+  )
+    passed++;
+  else failed++;
+
+  if (
+    test('observer-loop closes stdin on the backgrounded claude analysis call (#2452)', () => {
+      const observerLoopSource = fs.readFileSync(path.join(__dirname, '..', '..', 'skills', 'continuous-learning-v2', 'agents', 'observer-loop.sh'), 'utf8');
+
+      assert.ok(observerLoopSource.includes('-p "$prompt_content" < /dev/null'), 'observer-loop should close stdin on the backgrounded claude call so Git Bash children do not hang on inherited stdin and exit 1');
+    })
+  )
+    passed++;
+  else failed++;
+
   if (SKIP_BASH) {
     console.log('  ⊘ detect-project exports the resolved Python command (skipped on Windows)');
     passed++;