Fails to compile because stdio.h uses C99 features

[scudo005]

The validation fails on stdio.h because it now uses C99 features:

extern FILE *fopen (const char *__restrict __filename,
		    const char *__restrict __modes)

__restrict is a C99 feature, and this compiler only supports C89.

[scudo005]

(This is only meant as information to people wanting to build this software today, so they can know that this is a pitfall they can encounter.)