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AbacusAvenger | 2 years ago
There are a ton of background services that periodically spin up for no obvious reason, consuming a ton of CPU for a few minutes at a time, then go back to idle. I don't know what they're doing or why. Luckily since they're background services, they're bound to the efficiency cores on Apple Silicon, so they don't hurt battery life or thermals too much most of the time.
And as far as bugs go, the worst part is that bug reports through the Feedback app go largely ignored and bugs seem to keep accumulating. Even for bugs with clear and well-documented repro cases, Apple doesn't seem to pay any attention.
I'm a game developer, so the majority of my bug reports come from issues I've experienced with the graphics drivers or with Xcode. Here's a few examples:
- On macOS devices with > 60Hz displays, there is some awful stuttering with Metal apps in full screen mode. For some reason, CAMetalLayer nextDrawable sometimes just takes a very long time whenever it uses direct-to-display mode for presentation. That mode is implicitly enabled for full screen Metal apps, in order to bypass the display compositor and theoretically reduce latency. This bug also applies to MacBooks with the built in "ProMotion" (120Hz) displays. I'd be perfectly happy if there was just some flag to say "don't use direct-to-display", but if there is one, it's not documented anywhere. I haven't found a workaround yet. I originally reported this in August 2022. Apple replied once in October 2022 to say "we can't reproduce this, please provide a demo app". I provided the app that reliably reproduces the problem within an hour of their reply, but they've been silent since.
- Metal and OpenGL (the latter is emulated via Metal on Apple Silicon Macs) both exhibit a bug with triangle merging that causes partial derivatives to go very wrong along primitive edges. There's a usable workaround for this on the Metal side (just enable a [[sample_mask]] even if you're not doing multisampling). There's no such workaround for the OpenGL side, unfortunately. I was able to work with Asahi Lina to fix this for Mesa on Asahi Linux, and the fix itself was actually really trivial and didn't require a sample mask hack (it took a lot of debugging to figure out, though -- but that's how reverse engineering goes). To solve it, Apple would simply need to set a particular bit to disable triangle merging whenever the fragment shader uses derivatives. I reported this issue in December 2022, and Apple hasn't replied.
- This one is not as egregious as some of the bugs I've reported, and the Xcode team has responded reliably in the past. This is the first Xcode bug report I've had where they didn't acknowledge the report within ~14 days or so. In the current Xcode beta, using the graphics debugger will suspend the app but hitting "resume" leaves the app stuck suspended. The normal application debugger path does not do this, just the graphics debugger. I reported this in mid-June 2023, but haven't heard anything yet.
Pulcinella|2 years ago
This came up on the ATP podcast recently. Feedback is a very, very crappy front-end for Apple's internal bug tracker Radar (which itself I've heard is not great).
Long story short, you have to submit an entirely new bug report through Feedback with the sample project attached. Apple's developers basically can't see replies to Feedbacks.
I believe the reason has to do with fears over GDPR and data collection. The Feedbacks are scrubbed of any kind of personal or identifying information before they are re-entered into Radar. I don't understand all the reasons, but I 100% agree this is absolutely nuts and not an appropriate way to manage bug reports.
internetter|2 years ago