fix(executor): filter codex_core stderr noise

fix(executor): unset CLAUDECODE env to prevent nested session rejection

codeagent-wrapper/internal/app/executor_concurrent_test.go

@@ -169,6 +169,12 @@ func (f *execFakeRunner) Process() executor.ProcessHandle {
 	return &execFakeProcess{pid: 1}
 }
 
+func (f *execFakeRunner) UnsetEnv(keys ...string) {
+	for _, k := range keys {
+		delete(f.env, k)
+	}
+}
+
 func TestExecutorRunCodexTaskWithContext(t *testing.T) {
 	defer resetTestHooks()
 

codeagent-wrapper/internal/app/main_test.go

@@ -274,6 +274,10 @@ func (d *drainBlockingCmd) Process() executor.ProcessHandle {
 	return d.inner.Process()
 }
 
+func (d *drainBlockingCmd) UnsetEnv(keys ...string) {
+	d.inner.UnsetEnv(keys...)
+}
+
 type bufferWriteCloser struct {
 	buf    bytes.Buffer
 	mu     sync.Mutex
@@ -568,6 +572,14 @@ func (f *fakeCmd) Process() executor.ProcessHandle {
 	return f.process
 }
 
+func (f *fakeCmd) UnsetEnv(keys ...string) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	for _, k := range keys {
+		delete(f.env, k)
+	}
+}
+
 func (f *fakeCmd) runStdoutScript() {
 	if len(f.stdoutPlan) == 0 {
 		if !f.keepStdoutOpen {

codeagent-wrapper/internal/executor/env_stderr_test.go

@@ -41,6 +41,11 @@ func (f *fakeCmd) SetEnv(env map[string]string) {
 	}
 }
 func (f *fakeCmd) Process() processHandle { return nil }
+func (f *fakeCmd) UnsetEnv(keys ...string) {
+	for _, k := range keys {
+		delete(f.env, k)
+	}
+}
 
 func TestEnvInjection_LogsToStderrAndMasksKey(t *testing.T) {
 	// Arrange ~/.codeagent/models.json via HOME override.

codeagent-wrapper/internal/executor/executor.go

@@ -113,6 +113,7 @@ type commandRunner interface {
 	SetStderr(io.Writer)
 	SetDir(string)
 	SetEnv(env map[string]string)
+	UnsetEnv(keys ...string)
 	Process() processHandle
 }
 
@@ -221,6 +222,33 @@ func (r *realCmd) SetEnv(env map[string]string) {
 	r.cmd.Env = out
 }
 
+func (r *realCmd) UnsetEnv(keys ...string) {
+	if r == nil || r.cmd == nil || len(keys) == 0 {
+		return
+	}
+	// If cmd.Env is nil, Go inherits all parent env vars.
+	// Populate explicitly so we can selectively remove keys.
+	if r.cmd.Env == nil {
+		r.cmd.Env = os.Environ()
+	}
+	drop := make(map[string]struct{}, len(keys))
+	for _, k := range keys {
+		drop[k] = struct{}{}
+	}
+	filtered := make([]string, 0, len(r.cmd.Env))
+	for _, kv := range r.cmd.Env {
+		idx := strings.IndexByte(kv, '=')
+		name := kv
+		if idx >= 0 {
+			name = kv[:idx]
+		}
+		if _, ok := drop[name]; !ok {
+			filtered = append(filtered, kv)
+		}
+	}
+	r.cmd.Env = filtered
+}
+
 func (r *realCmd) Process() processHandle {
 	if r == nil || r.cmd == nil || r.cmd.Process == nil {
 		return nil
@@ -1126,6 +1154,13 @@ func RunCodexTaskWithContext(parentCtx context.Context, taskSpec TaskSpec, backe
 
 	injectTempEnv(cmd)
 
+	// Claude Code sets CLAUDECODE=1 in its child processes. If we don't
+	// remove it, the spawned `claude -p` detects the variable and refuses
+	// to start ("cannot be launched inside another Claude Code session").
+	if commandName == "claude" {
+		cmd.UnsetEnv("CLAUDECODE")
+	}
+
 	// For backends that don't support -C flag (claude, gemini), set working directory via cmd.Dir
 	// Codex passes workdir via -C flag, so we skip setting Dir for it to avoid conflicts
 	if cfg.Mode != "resume" && commandName != "codex" && cfg.WorkDir != "" {

codeagent-wrapper/internal/executor/filter.go

@@ -20,8 +20,7 @@ var geminiNoisePatterns = []string{
 
 // codexNoisePatterns contains stderr patterns to filter for codex backend
 var codexNoisePatterns = []string{
-	"ERROR codex_core::codex: needs_follow_up:",
+	"ERROR codex_core::",
-	"ERROR codex_core::skills::loader:",
 }
 
 // filteringWriter wraps an io.Writer and filters out lines matching patterns

codeagent-wrapper/internal/executor/filter_test.go

@@ -71,3 +71,35 @@ func TestFilteringWriterPartialLines(t *testing.T) {
 		t.Errorf("got %q, want %q", got, "Hello World\n")
 	}
 }
+
+func TestFilteringWriterCodexNoise(t *testing.T) {
+	tests := []struct {
+		name  string
+		input string
+		want  string
+	}{
+		{
+			name:  "filter all codex_core errors",
+			input: "ERROR codex_core::rollout::list: state db missing rollout path for thread 123\nERROR codex_core::skills::loader: missing skill\nVisible output\n",
+			want:  "Visible output\n",
+		},
+		{
+			name:  "keep non codex_core errors",
+			input: "ERROR another_module::state: real failure\nERROR codex_core::codex: needs_follow_up: true\nDone\n",
+			want:  "ERROR another_module::state: real failure\nDone\n",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var buf bytes.Buffer
+			fw := newFilteringWriter(&buf, codexNoisePatterns)
+			_, _ = fw.Write([]byte(tt.input))
+			fw.Flush()
+
+			if got := buf.String(); got != tt.want {
+				t.Errorf("got %q, want %q", got, tt.want)
+			}
+		})
+	}
+}