trainer_interface.cc: Integer value -1 is outside the valid range of values [0, 255] for the enumeration type 'ScriptType'

[kcoul]

When building with C++ '20.
Error due to default of "-1" on L221-222

  constexpr unicode_script::ScriptType kAnyType =
      static_cast<unicode_script::ScriptType>(-1);

[kcoul]

Temporary workaround for anyone facing the same issue:

Add to CMakeLists.txt
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-enum-constexpr-conversion" )