CMake Warning \(policy\) at .*/Warn-Unset-Macro-Multi\.cmake:[0-9]+ \(cmp0219_warn_macro\):
  Policy CMP0219 is not set: Macro invocations preserve backslashes in
  arguments\.  Run "cmake --help-policy CMP0219" for policy details\.  Use the
  cmake_policy command to set the policy and suppress this warning\.

  Command "cmp0219_warn_macro" called with arguments containing backslashes\.

  Since the policy is not set, backslashes in the arguments:

   "prefix\\tsuffix"
   "left\\;right"

  will be interpreted as escape sequences for compatibility\.

  Set the policy to NEW to instead pass

   "prefix\\\\tsuffix"
   "left\\\\;right"

  so that argument parsing will preserve the original values\.
This warning is for project developers\.  Use -Wno-author or -Wno-policy to
suppress it\.
