evmar

Recently bought something online from Home Depot and it arrived damaged. When I asked them for help they said I had to drive it back to the store myself.

If I have to drive to the store to get it, I wouldn’t have shopped with them! It feels like every time I don’t order with Amazon the stores remind me why I ought to.

I moved from a rich city social life to a lonely suburban one (I have regrets, there are complicating factors). I met a fellow dad who mentioned a book as we started chatting and I was excited (someone who reads!).

As we talked about this very isolation problem he told me about his neighbors who kept inviting him over and offering to watch the kids for him and how he thought it was just weird and couldn’t trust them. It broke my heart — I could just imagine the neighbors trying to be good to their community and that very behavior is met with distrust.

(I read half the book he mentioned and asked him about it the next time I saw him. Turns out he hadn’t read the book, just heard about it on a podcast. My quest to meet someone who reads continues.)

A trick I learned from an east bay friend is that (when possible) the bus across the bridge is way nicer than the BART under the bay, especially around sunset.

I think the Rust feature you’re looking for regarding recompiling the standard library is called “build-std”, that should be enough for you to search for it. (For similar reasons you also need that flag if you are trying to use Rust to build multithreaded wasm binaries, so it might come up for you!)

Totally agree. I saw the idea of “Internet Kessler syndrome” recently and I can’t stop thinking about how it captures this.

Thanks for saying this! I am close enough to it that I mostly remember all of the bad decisions I made that are now unfixable, haha.

Yes, I don’t remember the details but vaguely remember that CMake tends to group things together that could in principle be made more parallel, as you mention with generates files in a library. On the other hand if build2 makes it easier for authors to express these kinds of patterns without the serialization then I count that as a win for build2!

[Ninja author here] Nice post, cool to see the deep dive! I also appreciate the details on how they produced their numbers.

As they observe, Ninja gets to be fast mostly by cheating: it avoids a lot of work by saying many things are just out of scope for Ninja to do, and that means it is a useful a target to race against. (Funny thing: when I wrote Ninja I was misremembering how fast an earlier build system was so I kept trying to make it faster. So don't treat it as a lower bound, I just made it up!)

I comment here to say I find the explanation for 'why' in this post unsatisfying. They mention three design decisions.

The first one is a criticism of CMake, not Ninja (?), so I don't think it can be why. I might have misunderstood?

The second reason given is doing some work like header dependencies in multiple threads. This is the most plausible reason to me but it still feels unlikely. It's a very small amount of work: the post mentions 300 compiles, so maybe parsing 300 small text files?

The third is that they run the compiler up front an additional time to gather headers, which is strictly more work than Ninja. There is some hand waving about file access patterns but I am skeptical; if the end-to-end build time is 3 seconds then the project is small enough to all fit in kernel caches. They also mention doing other things like invoking the compiler to get version information. This seems like it would dwarf any performance gain from number 2.

Maybe it's just my own curiosity, I think this post would be better if it had a better explanation for the reason. I'm not disputing the result, I just think the result should make you suspicious that something else is going on, and you might learn something from that! You could for example explore whether it's the header dependency thing by profiling the Ninja invocation and seeing if it's waiting for CPU or waiting for tasks to execute.

(If I had to guess without looking at any of the involved code, I would predict it's something about how CMake generates the build, like it introduces serialization in a place where build2 is parallel, or it adds some extra build steps like gathering the current git hash into a header file or something.)

If you imagine Google's job is to present useful information, these blogs that are maximizing cash while simulating usefulness are exactly the sorts of things I would hope Google to want to filter out.

(I don't think Google's often capricious ranking changes really succeed at this, but the outcomes in this post seems like something hypothetically good?)