stderr property
Stderr is what the program wrote to standard error, INCLUDING a compiler's diagnostics and the trace of a program that exited non-zero. Its presence is not a failed call.
Please note: This property should have been non-nullable! Since the specification file does not include a default value (using the "default:" property), however, the generated source code must fall back to having a nullable type. Consider adding a "default:" property in the specification file to hide this note.
Implementation
String? stderr;