Can I use a key starting with underscore?

[dimitre]

It seems to be a valid JSON using a validator:

{
	"_openFrameworksProjectGeneratorVersion": "45"
}

but in some systems while running actions I found a strange issue:

Creating project files for osx
terminate called after throwing an instance of 'nlohmann::json_abi_v3_11_2::detail::parse_error'
  what():  [json.exception.parse_error.109] parse error: array index '_openFrameworksProjectGeneratorVersion' is not a number
/home/runner/work/openFrameworks/openFrameworks/scripts/dev/create_package.sh: line 176: 24002 Aborted

Is it OK to use a key starting with an underscore?
Thanks

[gregmarr]

While it says parse_error in the type, it's actually an error in json_pointer handling. You have used _openFrameworksProjectGeneratorVersion to try to access an array instead of an object.