ddidderr
4eb03f637d
Adds tools/difftest: a Zig driver built against a copy of Ghostty 1.3.1's own src/terminal (Zig 0.15.2, set up under target/ by tools/difftest/setup.sh) and a Rust twin on ghostty-terminal, both printing a canonical dump of every scrollback/active row (cells, graphemes, styles, hyperlinks, row flags), cursor, modes, regions, tabstops and colors. A seeded generator produces escape-heavy streams (UTF-8/wide/combining/emoji, C0, CSI with edge params, SGR, modes, ESC, OSC, DCS, margins, insert/delete); `just difftest` runs it with Zig assertions on (ReleaseSafe vs debug Rust) and off (ReleaseFast vs production Rust), with minimizers and a triage script. Divergences found and fixed in Rust (each with a regression test): - ill-formed UTF-8 decoding follows the SIMD path a default Ghostty build uses (not Zig's scalar fallback) - PageList::erase_rows keeps Zig's row-flag behavior on regrow - grapheme move on wrap with left/right margins uses the original cell Upstream bugs found and deliberately NOT replicated (per the project rule): a stale cell pointer after page growth in Terminal.zig:482/539 that drops a grapheme, plus several Zig assertion failures/segfaults; documented with minimized repros in docs/rewrite/notes/difftest-DF.md. Final run: 390k cases across many geometries, 0 divergences (Zig-abort cases, ~0.1-0.5%, are not compared). Test Plan: - just difftest 20000 "1 2 3" - cargo test -p ghostty-terminal (regression tests)
ghostty-rs
A Rust rewrite of the Ghostty 1.3.1 terminal emulator for Linux (GTK4 + libadwaita, OpenGL).
It aims for behavioural parity with Ghostty: the same configuration file
format, options, defaults and documentation; the same keybindings and
actions; the same ghostty +action CLI; the same terminal emulation
(including kitty keyboard/graphics protocols, OSC 8 hyperlinks, semantic
prompts, synchronized output, tmux control mode); the same shell
integration, themes and terminfo.
Out of scope: macOS, Windows, WASM, the embedded libghostty C API, and
Sentry crash reporting (disabled by default on Linux upstream).
Building and running
Requirements: Rust (edition 2024), GTK ≥ 4.14, libadwaita ≥ 1.5,
fontconfig, freetype, harfbuzz, Oniguruma, libepoxy, blueprint-compiler
and glib-compile-resources at build time.
cargo run # open a terminal window running your shell
cargo run -- -e htop # run a command
cargo run -- +list-themes # CLI actions work like Ghostty's
cargo run --profile production # optimized build (LTO, no debug assertions)
Development builds find resources/ (shell integration, themes, terminfo)
automatically. Your existing Ghostty config
(~/.config/ghostty/config[.ghostty]) is used as-is.
Installing
just install /usr/local # binary, share/ghostty, terminfo, desktop files,
# completions, man pages, translations, icons
just install /usr false true # system-package layout (lib/systemd/user)
Testing
just test # cargo test --workspace (~3000 tests)
just clippy # clippy with -D warnings
Every Zig test block of the ported files was ported to a Rust test.
crates/ghostty-core/tests holds end-to-end tests that drive the real core,
terminal and a real pty through a fake app runtime. ghostty-bench mirrors
Ghostty's benchmark tool; terminal stream throughput is on par with the Zig
build (see docs/rewrite/notes/perf-P1.md).
Documentation
docs/rewrite/ARCHITECTURE.md– top-down decomposition, crate map, key design decisions, intentional omissionsdocs/rewrite/STATUS.md– work package historydocs/rewrite/notes/– per-crate porting notes, deviations from Zig, audits and verification reports
License
MIT, like Ghostty. Bundled fonts and themes carry their own licenses (see
crates/ghostty-font/res/ and resources/themes/).