Jakub KonkaandCole Miller
16dfc60ad2
Here's some backstory: * on macOS, @cole-miller and I noticed that since roughly Oct 2025, due to some changes to latest macOS Tahoe, for any spawned child process we needed to reset Mach exception ports (https://github.com/zed-industries/zed/issues/36754 + https://github.com/RemiKalbe/zed/commit/6e8f2d2ebe5a93753625a3026aeb996de8cb436b) * the changes in that PR achieve that via `pre_exec` hook on `std::process::Command` which then abandons `posix_spawn` syscall for `fork` + `execve` dance on macOS (we tracked it down in Rust's std implementation) * as it turns out, `fork` + `execve` is pretty expensive on macOS (apparently way more so than on other OSes like Linux) and `fork` takes a process-wide lock on the allocator which is bad * however, since we wanna reset exception ports on the child, the only official way supported by Rust's std is to use `pre_exec` hook * posix_spawn on macOS exposes this tho via a macOS specific extension to that syscall `posix_spawnattr_setexceptionports_np` but there is no way to use that via any standard interfaces in `std::process::Command` * thus, it seemed like a good idea to instead create our own custom Command wrapper that on non-macOS hosts is a zero-cost wrapper of `smol::process::Command`, while on macOS we reimplement the minimum to achieve `smol::process::Command` with `posix_spawn` under-the-hood Notably, this changeset improves git-blame in very large repos significantly. Release Notes: - Fixed performance spawning child processes on macOS by always forcing `posix_spawn` no matter what. --------- Co-authored-by: Cole Miller <cole@zed.dev>
Zed
Welcome to Zed, a high-performance, multiplayer code editor from the creators of Atom and Tree-sitter.
Installation
On macOS, Linux, and Windows you can download Zed directly or install Zed via your local package manager (macOS/Linux/Windows).
Other platforms are not yet available:
- Web (tracking issue)
Developing Zed
Contributing
See CONTRIBUTING.md for ways you can contribute to Zed.
Also... we're hiring! Check out our jobs page for open roles.
Licensing
License information for third party dependencies must be correctly provided for CI to pass.
We use cargo-about to automatically comply with open source licenses. If CI is failing, check the following:
- Is it showing a
no license specifiederror for a crate you've created? If so, addpublish = falseunder[package]in your crate's Cargo.toml. - Is the error
failed to satisfy license requirementsfor a dependency? If so, first determine what license the project has and whether this system is sufficient to comply with this license's requirements. If you're unsure, ask a lawyer. Once you've verified that this system is acceptable add the license's SPDX identifier to theacceptedarray inscript/licenses/zed-licenses.toml. - Is
cargo-aboutunable to find the license for a dependency? If so, add a clarification field at the end ofscript/licenses/zed-licenses.toml, as specified in the cargo-about book.
Sponsorship
Zed is developed by Zed Industries, Inc., a for-profit company.
If you’d like to financially support the project, you can do so via GitHub Sponsors. Sponsorships go directly to Zed Industries and are used as general company revenue. There are no perks or entitlements associated with sponsorship.