zed/crates/libghostty-vt-sys

libghostty-vt-sys

Raw FFI bindings for libghostty-vt, the Ghostty terminal emulation library.

Zed depends on the published libghostty-vt Rust crate, but patches its libghostty-vt-sys dependency to this local crate via [patch.crates-io]. The wrapper crate stays external; this sys crate is vendored only because Zed needs different build behavior than the published sys crate currently provides.

Why this crate is vendored

• Zed must bundle the terminal backend. Users should not need to install Ghostty, place a Ghostty dynamic library on their system, or configure a runtime library path for Zed to start.
• Zed needs a static libghostty-vt.a build so release artifacts can link the backend into Zed directly.
• The Ghostty source revision must be pinned and reproducible for CI and release builds.
• The build has to link Ghostty's static native dependencies (simdutf and highway) explicitly.
• On macOS, Zed still targets older systems than Ghostty's default Zig build target. For fetched sources, this crate patches Ghostty's deployment target from macOS 13 to macOS 11 before building.
• The generated FFI bindings are checked in so regular builds and docs.rs do not need bindgen or a Zig toolchain just to type-check the Rust API surface.

Build behavior

By default, build.rs fetches ghostty-org/ghostty at the pinned commit in GHOSTTY_COMMIT, builds it with:

zig build -Demit-lib-vt --prefix <out-dir>/ghostty-install

and links:

• libghostty-vt.a
• libsimdutf.a
• libhighway.a

Set GHOSTTY_SOURCE_DIR to point at a local Ghostty checkout while developing or testing a newer Ghostty revision. When this override is used, the source is treated as external and the macOS deployment-target patch is not applied; point it at an already-patched checkout if you need the macOS 11 target.

Removing the patch

This vendored sys crate should go away once the published libghostty-vt-sys crate supports the requirements above directly: static bundled builds, explicit static dependency linkage, a Zed-compatible macOS deployment target, pinned-source or otherwise reproducible release builds, and checked-in bindings suitable for docs and CI.