nimble test gets stuck when using wl-copy command

[fox0430]

OS: Arch Linux
nim version: 2.2.4
nimble version: 0.18.2
wl-clipboard version: 2.2.1

import std/[unittest, os]

test "wl-copy":
  echo execShellCmd("printf '' | wl-copy") == 0

It gets stuck in the following state, and it worked fine in nimble 0.16.4.

$ nimble test
  Compiling /home/user/test/tests/test (from package test) using c backend
      Info: compiling nim package using /home/user/.nimble/bin/nim
    Working ⣷

It seems to be stuck after the command is executed because when I look at the clipboard contents it is reset.