anchor.diff:  
     postPatch = ''
       substituteInPlace tools/hid2hci.rules \
  -      --replace /sbin/udevadm ${systemd}/bin/udevadm \
  +      --replace /sbin/udevadm ${systemdMinimal}/bin/udevadm \
         --replace "hid2hci " "$out/lib/udev/hid2hci "
       # Disable some tests:
       # - test-mesh-crypto depends on the following kernel settings:
  
positive.code: , pkg-config
  , python3
  , readline
  , systemd
  , udev
  , withExperimental ? false
  }: let
  
negative.code: 
    doCheck = stdenv.hostPlatform.isx86_64;
  
    postInstall = ''
      mkdir -p $test/{bin,test}
      cp -a test $test
      pushd $test/test
  