> is this really a big deal given you run ./configure once

I end up running it dozens of times when changing versions, checking out different branches, chasing dependencies.

It’s a big deal.

> it's like systemd trading off non-determinism for boot speed, when it takes 5 minutes to get through the POST

5 minute POST time is a bad analogy. systemd is used in many places, from desktops (that POST quickly) to embedded systems where boot time is critical.

If deterministic boot is important then you would specify it explicitly. Relying on emergent behavior for consistent boot order is bad design.

The number of systems that have 5 minute POST times and need deterministic boot is an edge case of an edge case.

>chasing dependencies.

This aspect of configure, in particular, drives me nuts. Obviously I'd like it to be faster, but it's not the end of the world. I forget what I was trying to build the other week, but I had to make 18 separate runs of configure to find all the things I was missing. When I dug into things it looked like it could probably have done it in 2 runs, each presenting a batch of things that were missing. Instead I got stuck with "configure, install missing package" over and over again.

> to embedded systems where boot time is critical.

if it's critical on an embedded system then you're not running systemd at all

> The number of systems that have 5 minute POST times and need deterministic boot is an edge case of an edge case.

desktop machines are the edge case, there's a LOT more servers running Linux than people using Linux desktops

> Relying on emergent behavior for consistent boot order is bad design.

tell that to the distro authors who 10 years in can't tell the difference between network-online.target, network-pre.target, network.target

> from desktops (that POST quickly)

I take you don't run DDR5?

> I end up running it dozens of times when changing versions, checking out different branches, chasing dependencies.

Yeah... but neither of that is going to change stuff like the size of a data type, the endianness of the architecture you're running on, or the features / build configuration of some library the project depends on.

Parallelization is a bandaid (although a sorely needed!) IMHO, C/C++ libraries desperately need to develop some sort of standard that doesn't require a full gcc build for each tiny test. I'd envision something like nodejs's package.json, just with more specific information about the build details themselves. And for the stuff like datatype sizes, that should be provided by gcc/llvm in a fast-parseable way so that autotools can pick it up.