Hiya folks! I'm David and I work on rust-analyzer, which is a language server for Rust similar to sourcekit-lsp. I'm using the new Instruments profiling tooling functionality in Xcode 16.3 and Xcode 26 (Processor Trace and CPU Counters) to profile our trait solver/type checker. While I've been able to use the new CPU Counters instrument successfully (the CPU Bottleneck feature is incredible! Props to the team!), I've been unable to make use of the Processor Trace instrument. Instruments gives me the error message "Processor Trace cannot profile this process without proper permissions". The diagnostic suggests adding the com.apple.security-get-task-allow entitlement to the code I'm trying to profile, or ensure that the build setting CODE_SIGN_INJECT_BASE_ENTITLEMENTS = YES is enabled in Xcode. Unfortunately, I don't know how I can add that entitlement to a self-signed binary produced by Cargo and I'm not using Xcode for somewhat obvious reasons. Here's some information about my setup: Instruments Version 26.0 (17A5241e) I'm on an 14" MacBook Pro with M4 Pro. It's running macOS Version 26.0 Beta (25A5295e). I've enabled the "Processor Trace" feature in "Developer Tools" and even added the Instruments application to "Developer Tools". As a last-ditch effort before posting this, I disabled SIP on my Mac. Didn't help. To reproduce my issue: Get Rust via https://rustup.rs/. Clone rust-analyzer: git clone https://github.com/rust-lang/rust-analyzer.git. cd rust-analyzer Run cargo test --package hir-ty --lib --profile=dev-rel -- tests::incremental::add_struct_invalidates_trait_solve --exact --show-output. By default, this command will output a bunch of build progress with the output containing something like Running unittests src/lib.rs (target/dev-rel/deps/hir_ty-f1dbf1b1d36575fe). I take the absolute path of that hir_ty-$SOME-HASH string (in my case, it looks like /Users/dbarsky/Developer/rust-analyzer/target/dev-rel/deps/hir_ty-f1dbf1b1d36575fe) and add it to the "Launch" profile. To the arguments section, I add --exact tests::incremental::add_struct_invalidates_trait_solve. I then try to record/profile via Instruments, but then I get the error message I shared above. Below is output of codesign -dvvv: ❯ codesign -dvvv target/dev-rel/deps/hir_ty-f1dbf1b1d36575fe Executable=/Users/dbarsky/Developer/rust-analyzer/target/dev-rel/deps/hir_ty-f1dbf1b1d36575fe Identifier=hir_ty-f1dbf1b1d36575fe Format=Mach-O thin (arm64) CodeDirectory v=20400 size=140368 flags=0x20002(adhoc,linker-signed) hashes=4383+0 location=embedded Hash type=sha256 size=32 CandidateCDHash sha256=99e96c8622c7e20518617c66a7d4144dc0daef28 CandidateCDHashFull sha256=99e96c8622c7e20518617c66a7d4144dc0daef28f22fac013c28a784571ce1df Hash choices=sha256 CMSDigest=99e96c8622c7e20518617c66a7d4144dc0daef28f22fac013c28a784571ce1df CMSDigestType=2 CDHash=99e96c8622c7e20518617c66a7d4144dc0daef28 Signature=adhoc Info.plist=not bound TeamIdentifier=not set Sealed Resources=none Internal requirements=none Any tips would be welcome! Additionally—and perhaps somewhat naively—I think I'd expect the Processor Trace instrument to just work with an adhoc-signed binary, as lldb and friends largely do—I'm not sure that such a high barrier for CPU perf counters is warranted, especially on an adhoc-signed binary.

Hi folks! I'm David Barsky and I work on rust-analyzer, which is the IDE for the Rust programming language. For a while, we've had issues with VS Code not sending the correct changed files to the language server (such as changing commits or rebasing), so I started using rust-analyzer's native, off-by-default file watching functionality that binds to FSEvent via the notify library. This has helped a bunch, but I'm not sure how completely reliable it is. Before I consider changing the default file watching behavior for our (many!) users, I wanted to check: is it possible to combine "walk & watch" into a single, atomic operation? My goal is that upon getting a notification for a file change event, rust-analyzer can read the changed file and not worry about TOCTOU-esque conditions (rust-analyzer has a pretty robust incremental computation system, so we're able to invalidate changes pretty reliably). That being said, based off: this response from Quinn "The Eskimo!" about 8 years ago, and FSEventStreamCallback being a bit limited in the number of args, ...it seems like the answer appears to be "no". (I'm also familiar with Watchman, but it'd be great if the big pile of heuristics that Watchman uses were less necessary.)