undefined): mystrncat (buffer, ...)
mystrncat.c:13:13: Passed storage b not completely defined (*b is undefined):
mystrncat (b, ...)
+ mystrncat.c:10:3: Storage *b allocated
mystrncat.c:12:3: Possible out-of-bounds store:
mystrncat(buffer, str, sizeof((buffer)) - 1)
Unable to resolve constraint: