diff --git a/_demo/osproc/exec.go b/_cmptest/osproc/exec.go
similarity index 93%
rename from _demo/osproc/exec.go
rename to _cmptest/osproc/exec.go
index b5217028..35bddf8f 100644
--- a/_demo/osproc/exec.go
+++ b/_cmptest/osproc/exec.go
@@ -26,4 +26,5 @@ func main() {
 		return
 	}
 	proc.Wait()
+	fmt.Println("proc.Wait done")
 }
diff --git a/internal/lib/os/exec_unix.go b/internal/lib/os/exec_unix.go
index 2b2ac01c..f9063b4d 100644
--- a/internal/lib/os/exec_unix.go
+++ b/internal/lib/os/exec_unix.go
@@ -14,7 +14,6 @@ import (
 )
 
 func (p *Process) wait() (ps *ProcessState, err error) {
-	/* TODO(xsw):
 	if p.Pid == -1 {
 		return nil, syscall.EINVAL
 	}
@@ -58,8 +57,6 @@ func (p *Process) wait() (ps *ProcessState, err error) {
 		rusage: &rusage,
 	}
 	return ps, nil
-	*/
-	panic("todo: os.Process.wait")
 }
 
 func (p *Process) signal(sig Signal) error {
diff --git a/internal/lib/os/wait_unimp.go b/internal/lib/os/wait_unimp.go
new file mode 100644
index 00000000..810e35da
--- /dev/null
+++ b/internal/lib/os/wait_unimp.go
@@ -0,0 +1,21 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// aix, darwin, js/wasm, openbsd, solaris and wasip1/wasm don't implement
+// waitid/wait6.
+
+//go:build aix || darwin || (js && wasm) || openbsd || solaris || wasip1
+
+package os
+
+// blockUntilWaitable attempts to block until a call to p.Wait will
+// succeed immediately, and reports whether it has done so.
+// It does not actually call p.Wait.
+// This version is used on systems that do not implement waitid,
+// or where we have not implemented it yet. Note that this is racy:
+// a call to Process.Signal can in an extremely unlikely case send a
+// signal to the wrong process, see issue #13987.
+func (p *Process) blockUntilWaitable() (bool, error) {
+	return false, nil
+}
diff --git a/internal/lib/runtime/mfinal.go b/internal/lib/runtime/mfinal.go
index d75099b5..c3498f98 100644
--- a/internal/lib/runtime/mfinal.go
+++ b/internal/lib/runtime/mfinal.go
@@ -7,5 +7,6 @@
 package runtime
 
 func SetFinalizer(obj any, finalizer any) {
-	panic("todo: runtime.SetFinalizer")
+	// TODO(xsw):
+	// panic("todo: runtime.SetFinalizer")
 }