igraph functions can run into various problems preventing them from normal operation: the user might have supplied invalid arguments, eg. a non-square matrix when a square-matrix was expected, or the program has run out of memory while some more memory allocation is required, etc.

By default igraph aborts the program when it runs into an error. While this behavior might be good enough for smaller programs, it is without doubt avoidable in larger projects. Please read further if your project requires more sophisticated error handling. You can safely skip the rest of this chapter otherwise.