Incorrect format specifier usage.

[ni4]

There is a bunch of places with code like
sexp_error(sexp_exception_t::error, "Declared length was %d, but quoted string ended too early", (int) length, 0, count);.
Later it goes to snprintf, however it would use type size_t for c1 and c2 (%zu), not the %d like it is specified in the format string. Also (int) length doesn't make sense here as parameter would be converted to size_t.