> silently wrap around, producing incorrect and unpredictable

Now I'm more scared to use OpenBSD than I was a minute before.

I strongly prefer software that fails loudly and explicitly.

Yeah, that's pretty appalling.

Regardless of how good the philosophy of something is, if it's as niche and manpower constrained as OpenBSD is then it's going to accumulate problems like this.

I actually think this isn't even surprising from OpenBSD philosophically. They still subscribe to the Unix philosophy of old, moreso than FreeBSD and much much more than Linux.

That is, "worse is better" and it's okay to accept a somewhat leaky abstraction or less helpful diagnostics if it simplifies the implementation.

This is why `ed` doesn't bother to say anything but "?" to erroneous commands. If the user messes up, why should it be the job of the OS to handhold them? Garbage in, garbage out. That attitude may seem out of place today but consider that it came from a time when a program might have one author and 1-20 users, so their time was valued almost equally.

Even in that scenario that attitude seems out of place, considering a feature is implemented once and used many times.

> That attitude may seem out of place today

It absolutely doesn't. Everywhere I've worked we were instructed to give terse error messages to the user. Perhaps not a single "?", but "Oops, something went wrong!" is pretty widespread and equally unhelpful.

This is normal to return a terse message to a remote user via API. The remote user may be hostile, actively trying to gather information useful for breaking in.

But the local user who operates pf is already trusted, normally it would be root.

In either case, no error should be silently swallowed. Details should be logged in a secure way, else troubleshooting becomes orders of magnitude harder.

Code size would balloon if you try to format verbose error messages. I often look at the binaries of old EPROMs. I notice that 1) the amount of ASCII text is a big fraction of the binary 2) still just categories (“Illegal operation”). For the 1970s, we’re talking user programs that fit in 2K.

I write really verbose diagnostic messages in my modern code.

There was also an implicit saving back then that an error message could be looked up in some other system (typically, a printed manual). You didn't need to write 200 chars to the screen if you could display something much shorter, like SYS-3175, and be confident that the user could look that up in the manual and understand what they're being told and what to do about it.

IBM were experts at this, right up to the OS/2 days. And as machines got more powerful, it was easy to put in code to display the extra text by a lookup in a separate file/resource. Plus it made internationalization very easy.

> That attitude may seem out of place today

That attitude was out of place at every point. Now it was excusable when RAM and disk space was sparse, it isn't today, it have entirely drawbacks

It’s a fairly common issue with C code, so you should be scared about more than OpenBSD. As an example:

  a_long = an_int * another_int;

will do the multiplication in integers, then convert the result to long. That can produce surprising results of the multiplication overflows (I think that, technically, that would be undefined behavior, allowing the compiler to do what it wants, but most compilers will generate a multiplication instruction and let the CPU do whatever it does with int overflow (wrap around and trapping are the most popular options)

Also,

  an_int = a_long;

is valid, and will do a narrowing conversion. I don’t think compilers are required to warn about that.