panic(keyword)

The panic keyword like in rust is used to represent a bug that has happen in the program so that the program may exit safely and to avoid putting the program in a unstable state.

|main[]:
 panic("I Must panic.");

The panic keyword takes in only one argument a StringSpan or String.

Depending on the runtime the program may exit right after reaching a panic or only unwind the stack to call destructers and defers.