Re: [PATCH v3 6/6] Makefile: build "$(FUZZ_OBJS)" in CI, not under "all"

> > The current state is that regular devs are responsible for avoiding
> > compile breakages in the fuzz objects, even if they don't care
> > themselves. Your earlier patches turned this into: regular devs are not
> > on the hook for breaking fuzz objects; they are the responsibility of
> > fuzz people. I'm OK with either of those, but this approach seems to me
> > like the worst of both worlds. ;)
> >
> > If you do a refactor, you are still on the hook for breaking the fuzz
> > objects because CI will fail (and you have to investigate it, and fix it
> > for CI to remain a useful tool). But instead of finding out about the
> > problem quickly as you're working, instead you push up what you think is
> > a finished result, and then from minutes to hours later you get a
> > notification telling you that oops, you missed a spot. I find that the
> > shorter the error-fix-compile cycle is, the less time I waste waiting or
> > context-switching.
> >
> > If we had a ton of fuzz object files that took forever to build, the
> > savings on each build might be worth it. But AFAICT (from timing "make
> > clean; make -j1" before and after), we are saving less than 1% of the
> > build time (which is way less than the run-to-run noise).
> >
> > It doesn't seem like the right tradeoff to me. (Likewise, if other
> > CI-only checks we have, like coccinelle, could be run at a similar cost,
> > I'd recommend sticking them into the default developer build).
> 
> It's mainly psychological and doesn't contribute much to overall build
> time as a percentage, but I find it grating that the last thing I see
> before I switch away from that terminal when firing off a build on a
> slower GCC farm box I can only use -j1 on, is these fuzz objects taking
> 2-3 seconds to build, knowing I'm wasting time on something I'll never
> need.

> I think when we build something we should narrowly be compiling only the
> things we need, not running some sort of pseudo-CI on every developer's
> computer. We can have CI or other targets for that.
> 
> Besides, if we were going for some sane cost-benefit here we'd have
> targets to try compiling with NO_CURL=1 or some other conditional setups
> that are actually common in the wild.

> > One thing we _could_ do is stop building fuzz objects as part of "all",
> > but include them for DEVELOPER=1 builds (which includes CI). That keeps
> > them from hurting normal users (who don't actually need them), but
> > prevents bitrot. It doesn't address your original motivation though (you
> > as a developer would probably still be building them).
> 
> Please no. A very good thing about how DEVELOPER=1 works is that we're
> not doing anything extra except advisory compilation flags. It's turned
> on for "production" builds in a lot of settings because of that.