fix: inspector font/formatting, FreeType-only backend on Apple

Resolves the parity items of docs/rewrite/notes/review-rv17-codex.md
(final-Z20.md):
- FreeType-only font backend is also available on Apple targets
  (discovery-free, embedded emoji fonts); ghostty_surface_quicklook_font
  returns null for every backend except plain CoreText like Zig.
- The +list-fonts test keys off the font crate's selected backend
  (HAS_DISCOVERY), correct under feature unification and on Apple.
- Inspector font: 32 px rasterized with FreeType (dear-imgui freetype)
  like Ghostty; a new `visual-parity.sh inspector` scenario shows 0.031%
  differing pixels (hover highlight) vs the original on Linux. Windows,
  Apple and wasm keep stb_truetype at 32 px (registered as a deliberate
  deviation).
- Inspector DCS/APC descriptions follow Zig 0.15.2's formatting
  (checked by running Zig), incl. the terminal.Parser.Action prefix.
- The ImGui demo window appears only in dev-profile builds, mirroring
  Zig's .Debug-only gate.

Test Plan:
- cargo test --workspace --no-fail-fast (3582 passed)
- just check-macos (both, also with --features font-backend-freetype)
- scripts/visual-parity.sh inspector

Cargo.lock

@@ -706,8 +706,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "728af47c10cb2b12aa36b942e610f894ecafc5d61d0056ab61f9629f02b3d5dc"
 dependencies = [
  "cc",
+ "pkg-config",
  "serde",
  "serde_json",
+ "vcpkg",
 ]
 
 [[package]]

crates/ghostty-apprt-gtk/src/class/inspector_widget.rs

@@ -97,7 +97,7 @@ mod imp {
             let weak = obj.downgrade();
             obj.upcast_ref::<ImguiWidget>().set_hooks(
                 // Called to do initial setup of the UI.
-                Box::new(ghostty_inspector::setup),
+                Box::new(|ctx, _scale| ghostty_inspector::setup(ctx)),
                 // Called for every frame to draw the UI.
                 Box::new(move |ui| {
                     let Some(this) = weak.upgrade() else {

crates/ghostty-cli/src/list_fonts.rs

@@ -134,20 +134,28 @@ pub fn run(args: &[impl AsRef<[u8]>]) -> Result<u8, Error> {
 
 #[cfg(test)]
 mod tests {
+    /// Keyed off the font crate's actually selected backend, not this
+    /// crate's own feature flag: cargo feature unification can enable
+    /// `ghostty-font/font-backend-freetype` without the CLI forwarding
+    /// feature, and on Apple targets the default backend (CoreText) has
+    /// discovery.
+    ///
     /// Without a discovery mechanism (the `freetype` font backend, Zig
     /// `Discover == void`) `+list-fonts` prints the compile-time-option
     /// message and exits with 1, after parsing the arguments.
-    #[cfg(feature = "font-backend-freetype")]
     #[test]
-    fn freetype_backend_reports_no_discovery() {
-        const { assert!(!ghostty_font::HAS_DISCOVERY) };
-        assert_eq!(super::run(&[] as &[&[u8]]).expect("run"), 1);
-        assert!(super::NO_DISCOVERY_MESSAGE.ends_with("try again."));
-    }
-
-    #[cfg(not(feature = "font-backend-freetype"))]
-    #[test]
-    fn default_backend_has_discovery() {
-        const { assert!(ghostty_font::HAS_DISCOVERY) };
+    fn discovery_presence_follows_selected_backend() {
+        let backend = ghostty_font::options.backend;
+        assert_eq!(
+            ghostty_font::HAS_DISCOVERY,
+            backend.has_fontconfig() || backend.has_coretext()
+        );
+        if ghostty_font::HAS_DISCOVERY {
+            assert_ne!(backend, ghostty_font::Backend::Freetype);
+        } else {
+            assert_eq!(backend, ghostty_font::Backend::Freetype);
+            assert_eq!(super::run(&[] as &[&[u8]]).expect("run"), 1);
+            assert!(super::NO_DISCOVERY_MESSAGE.ends_with("try again."));
+        }
     }
 }

crates/ghostty-core/src/surface/mod.rs

@@ -745,6 +745,10 @@ impl Surface {
     #[cfg(target_vendor = "apple")]
     #[must_use]
     pub fn quicklook_font(&self, scale: f32) -> Option<*mut std::ffi::c_void> {
+        // For non-CoreText (and the other CoreText variants) we return none.
+        if ghostty_font::options.backend != ghostty_font::Backend::Coretext {
+            return None;
+        }
         let grid = self.renderer.font_grid();
         let mut state = grid.write();
         let face = state
@@ -752,12 +756,7 @@ impl Surface {
             .collection
             .get_face(ghostty_font::collection::Index::default())
             .ok()?;
-        let font = face.quicklook_font(f64::from(scale));
-        Some(
-            objc2_core_foundation::CFRetained::into_raw(font)
-                .as_ptr()
-                .cast(),
-        )
+        ghostty_font::face::quicklook_font_raw(face, f64::from(scale))
     }
 
     /// Current sizes.

crates/ghostty-font/Cargo.toml

@@ -40,7 +40,7 @@ harfbuzz-sys = { version = "0.8.0", features = ["bundled"] }
 # Like upstream (which builds them from source) the bundled copies are used,
 # so no system library is needed on macOS.
 freetype-sys = { version = "0.23.0", optional = true, features = ["bundled"] }
-harfbuzz-sys = { version = "0.8.0", optional = true, default-features = false, features = ["coretext", "bundled"] }
+harfbuzz-sys = { version = "0.8.0", optional = true, default-features = false, features = ["bundled"] }
 objc2 = "0.6.5"
 objc2-core-foundation = "0.3.2"
 objc2-core-graphics = "0.3.2"
@@ -51,18 +51,19 @@ objc2-foundation = "0.3.2"
 default = []
 # CoreText for discovery, FreeType for rendering, HarfBuzz for shaping
 # (Zig `-Dfont-backend=coretext_freetype`; Apple targets only).
-coretext-freetype = ["dep:freetype-sys", "dep:harfbuzz-sys", "harfbuzz-sys/freetype"]
+coretext-freetype = ["dep:freetype-sys", "dep:harfbuzz-sys", "harfbuzz-sys/freetype", "harfbuzz-sys/coretext"]
 # CoreText for discovery and rendering, HarfBuzz for shaping
 # (Zig `-Dfont-backend=coretext_harfbuzz`; Apple targets only).
-coretext-harfbuzz = ["dep:harfbuzz-sys"]
+coretext-harfbuzz = ["dep:harfbuzz-sys", "harfbuzz-sys/coretext"]
 # CoreText for discovery and rendering, no shaping
 # (Zig `-Dfont-backend=coretext_noshape`; Apple targets only).
 coretext-noshape = []
 # FreeType for rendering and HarfBuzz for shaping with no font discovery
-# (Zig `-Dfont-backend=freetype`; non-Apple, non-wasm targets only; the
-# default there is `fontconfig_freetype`). Not enabled by `--all-features`
-# in any meaningful sense: it switches the whole build to the backend.
-font-backend-freetype = []
+# (Zig `-Dfont-backend=freetype`; every target but wasm32, Apple included;
+# the default on Linux is `fontconfig_freetype`). Not enabled by
+# `--all-features` in any meaningful sense: it switches the whole build to
+# the backend.
+font-backend-freetype = ["dep:freetype-sys", "dep:harfbuzz-sys", "harfbuzz-sys/freetype"]
 
 # This crate wraps the freetype / harfbuzz / fontconfig C libraries through
 # their `-sys` crates; unsafe is denied by default and allowed on minimal,

crates/ghostty-font/build.rs

@@ -3,9 +3,10 @@
 //!
 //! Backends (see `src/backend.rs`):
 //! * Linux & other non-Apple, non-wasm targets: `fontconfig_freetype`.
-//! * Linux & other non-Apple, non-wasm targets with the cargo feature
+//! * Any non-wasm target (Apple included) with the cargo feature
 //!   `font-backend-freetype`: `freetype` (FreeType rendering, HarfBuzz
-//!   shaping, no font discovery; Zig `-Dfont-backend=freetype`).
+//!   shaping, no font discovery; Zig `-Dfont-backend=freetype`). On Apple
+//!   it takes precedence over the `coretext-*` features.
 //! * wasm32: `web_canvas`.
 //! * Apple targets: `coretext` (default), or via cargo features
 //!   `coretext-freetype`, `coretext-harfbuzz`, `coretext-noshape`.
@@ -46,14 +47,15 @@ fn main() {
     let ct_hb = feat("CORETEXT_HARFBUZZ");
     let ct_noshape = feat("CORETEXT_NOSHAPE");
 
+    // Zig `-Dfont-backend=freetype` is valid on every non-wasm target,
+    // Darwin included (no discovery, so the embedded emoji fonts are used).
     let ft_only = feat("FONT_BACKEND_FREETYPE");
-    if ft_only && (wasm || apple) {
-        println!(
-            "cargo:warning=feature `font-backend-freetype` only applies to non-Apple, \
-             non-wasm targets; ignored"
-        );
+    if ft_only && wasm {
+        println!("cargo:warning=feature `font-backend-freetype` does not apply to wasm32; ignored");
     }
-    let ft_only = ft_only && !wasm && !apple;
+    let ft_only = ft_only && !wasm;
+    // CoreText is the backend on Apple targets unless FreeType-only is asked.
+    let coretext = apple && !ft_only;
 
     let on = |c: &str, v: bool| {
         if v {
@@ -61,17 +63,17 @@ fn main() {
         }
     };
 
-    let freetype = !wasm && (!apple || ct_ft);
-    let harfbuzz = !wasm && (!apple || ct_ft || ct_hb);
+    let freetype = !wasm && (!coretext || ct_ft);
+    let harfbuzz = !wasm && (!coretext || ct_ft || ct_hb);
     on("font_freetype", freetype);
     let fontconfig = !wasm && !apple && !ft_only;
     on("font_fontconfig", fontconfig);
-    on("font_discovery", fontconfig || apple);
+    on("font_discovery", fontconfig || coretext);
     on("font_harfbuzz", harfbuzz);
-    on("font_coretext", apple);
-    on("font_coretext_face", apple && !ct_ft);
+    on("font_coretext", coretext);
+    on("font_coretext_face", coretext && !ct_ft);
     // The shaper is CoreText only for the plain `coretext` backend;
     // `coretext_noshape` uses the no-op shaper.
-    on("font_coretext_shaper", apple && !harfbuzz && !ct_noshape);
-    on("font_noshape", apple && !harfbuzz && ct_noshape);
+    on("font_coretext_shaper", coretext && !harfbuzz && !ct_noshape);
+    on("font_noshape", coretext && !harfbuzz && ct_noshape);
 }

crates/ghostty-font/src/backend.rs

@@ -13,9 +13,10 @@
 //!   (Zig: `-Dfont-backend=...`). "There is no scenario that is the default"
 //!   for those; they're only used by people who want to self-compile Ghostty
 //!   and prefer the freetype aesthetic.
-//! * Non-Apple, non-wasm targets with the cargo feature
+//! * Non-wasm targets (Apple included) with the cargo feature
 //!   `font-backend-freetype`: [`Backend::Freetype`] (Zig
-//!   `-Dfont-backend=freetype`: no font discovery).
+//!   `-Dfont-backend=freetype`: no font discovery; takes precedence over the
+//!   `coretext-*` features).
 //! * wasm32: [`Backend::WebCanvas`].
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -104,11 +105,7 @@ pub struct Options {
     pub backend: Backend,
 }
 
-#[cfg(all(
-    not(target_arch = "wasm32"),
-    not(target_vendor = "apple"),
-    feature = "font-backend-freetype"
-))]
+#[cfg(all(not(target_arch = "wasm32"), feature = "font-backend-freetype"))]
 pub const OPTIONS: Options = Options {
     backend: Backend::Freetype,
 };
@@ -122,13 +119,18 @@ pub const OPTIONS: Options = Options {
     backend: Backend::FontconfigFreetype,
 };
 
-#[cfg(all(target_vendor = "apple", feature = "coretext-freetype"))]
+#[cfg(all(
+    target_vendor = "apple",
+    feature = "coretext-freetype",
+    not(feature = "font-backend-freetype")
+))]
 pub const OPTIONS: Options = Options {
     backend: Backend::CoretextFreetype,
 };
 
 #[cfg(all(
     target_vendor = "apple",
+    not(feature = "font-backend-freetype"),
     feature = "coretext-harfbuzz",
     not(feature = "coretext-freetype")
 ))]
@@ -138,6 +140,7 @@ pub const OPTIONS: Options = Options {
 
 #[cfg(all(
     target_vendor = "apple",
+    not(feature = "font-backend-freetype"),
     feature = "coretext-noshape",
     not(feature = "coretext-freetype"),
     not(feature = "coretext-harfbuzz")
@@ -148,6 +151,7 @@ pub const OPTIONS: Options = Options {
 
 #[cfg(all(
     target_vendor = "apple",
+    not(feature = "font-backend-freetype"),
     not(feature = "coretext-freetype"),
     not(feature = "coretext-harfbuzz"),
     not(feature = "coretext-noshape")
@@ -165,6 +169,19 @@ pub const OPTIONS: Options = Options {
 mod tests {
     use super::*;
 
+    /// The `build.rs` cfgs must agree with the selected backend on every
+    /// target, including FreeType-only on Apple (Zig `Backend.has*`).
+    #[test]
+    fn selected_backend_matches_build_cfgs() {
+        let b = OPTIONS.backend;
+        assert_eq!(b.has_freetype(), cfg!(font_freetype));
+        assert_eq!(b.has_fontconfig(), cfg!(font_fontconfig));
+        assert_eq!(b.has_coretext(), cfg!(font_coretext));
+        assert_eq!(b.has_harfbuzz(), cfg!(font_harfbuzz));
+        assert_eq!(cfg!(font_discovery), b.has_fontconfig() || b.has_coretext());
+        assert_eq!(crate::HAS_DISCOVERY, cfg!(font_discovery));
+    }
+
     #[test]
     fn web_canvas_capabilities() {
         let b = Backend::WebCanvas;
@@ -236,11 +253,7 @@ mod tests {
         assert!(!b.has_coretext());
     }
 
-    #[cfg(all(
-        not(target_arch = "wasm32"),
-        not(target_vendor = "apple"),
-        feature = "font-backend-freetype"
-    ))]
+    #[cfg(all(not(target_arch = "wasm32"), feature = "font-backend-freetype"))]
     #[test]
     fn freetype_only_backend_selected() {
         let b = OPTIONS.backend;

crates/ghostty-font/src/face.rs

@@ -31,6 +31,25 @@ pub use ghostty_config::types_b::FreetypeLoadFlags;
 #[cfg(target_arch = "wasm32")]
 pub use web_canvas::Face;
 
+/// A retained `CTFontRef` of `face` for macOS quicklook (Zig
+/// `ghostty_surface_quicklook_font`, which only answers for the plain
+/// `.coretext` backend and returns null for every other one, FreeType-only
+/// included). The caller owns the reference.
+#[cfg(target_vendor = "apple")]
+#[must_use]
+pub fn quicklook_font_raw(face: &Face, scale: f64) -> Option<*mut std::ffi::c_void> {
+    #[cfg(font_coretext_face)]
+    if crate::backend::OPTIONS.backend == crate::Backend::Coretext {
+        return Some(
+            objc2_core_foundation::CFRetained::into_raw(face.quicklook_font(scale))
+                .as_ptr()
+                .cast(),
+        );
+    }
+    let _ = (face, scale);
+    None
+}
+
 /// If a DPI can't be calculated, this DPI is used. This is probably
 /// wrong on modern devices so it is highly recommended you get the DPI
 /// using whatever platform method you can.

crates/ghostty-inspector/Cargo.toml

@@ -13,6 +13,13 @@ ghostty-terminal.workspace = true
 ghostty-vt.workspace = true
 log = "0.4"
 
+# Zig builds Dear ImGui with `-DIMGUI_ENABLE_FREETYPE` (pkg/dcimgui), so the
+# inspector font is rasterized with FreeType. The `freetype` feature needs a
+# system FreeType (pkg-config); other targets keep stb_truetype (see
+# `docs/rewrite/DEVIANT_FIXES.md`).
+[target.'cfg(not(any(windows, target_vendor = "apple", target_arch = "wasm32")))'.dependencies]
+dear-imgui-rs = { version = "0.19", features = ["freetype"] }
+
 [lints.rust]
 unsafe_code = "deny"
 

crates/ghostty-inspector/build.rs

@@ -0,0 +1,14 @@
+//! Emits `cfg(ghostty_debug_build)` for the Cargo `dev` profile (Zig
+//! `builtin.mode == .Debug`). `debug_assertions` is not equivalent: the
+//! repository's `release` profile enables it, like Zig's `ReleaseSafe`.
+
+fn main() {
+    println!("cargo:rerun-if-changed=build.rs");
+    println!("cargo:rerun-if-env-changed=PROFILE");
+    println!("cargo:rustc-check-cfg=cfg(ghostty_debug_build)");
+    let profile = std::env::var("PROFILE").unwrap_or_default();
+    println!("cargo:rustc-env=GHOSTTY_BUILD_PROFILE={profile}");
+    if profile == "debug" {
+        println!("cargo:rustc-cfg=ghostty_debug_build");
+    }
+}

crates/ghostty-inspector/src/inspector.rs

@@ -2,18 +2,19 @@
 
 use std::sync::{Mutex, MutexGuard, PoisonError};
 
-use dear_imgui_rs::{ConfigFlags, Context, FontSource, StbTrueTypeFontData, Ui};
+use dear_imgui_rs::{ConfigFlags, Context, FontSource, Ui};
 use ghostty_renderer::{overlay::Feature, state::InspectorHook};
 use ghostty_terminal::terminal::Terminal;
 
 use crate::widgets;
 
+/// The inspector font size in pixels. Zig hardcodes `16 * 2` ("This is
+/// currently hardcoded to a 2x content scale", with a TODO to recalculate it
+/// for different screen DPIs); the style is scaled separately by the apprt.
+pub const FONT_SIZE: f32 = 16.0 * 2.0;
+
 /// Setup the ImGui state. This requires an ImGui context.
-///
-/// `scale_factor` is the content scale of the display; Zig hardcodes a 2x
-/// scale here (with a TODO) and sizes the font as `16 * 2`, this uses
-/// `16 * scale_factor` instead.
-pub fn setup(ctx: &mut Context, scale_factor: f64) {
+pub fn setup(ctx: &mut Context) {
     let io = ctx.io_mut();
 
     // Enable docking, which we use heavily for the UI. Our colorspace is
@@ -28,14 +29,28 @@ pub fn setup(ctx: &mut Context, scale_factor: f64) {
         log::warn!("failed to disable the imgui log file err={err}");
     }
 
-    // Use our own embedded font
-    let font_size = (16.0 * scale_factor.max(1.0)) as f32;
-    match StbTrueTypeFontData::from_slice(ghostty_font::embedded::REGULAR) {
-        Ok(data) => {
-            ctx.font_atlas()
-                .add_font(&[FontSource::stb_truetype_with_size(data, font_size)]);
+    // Use our own embedded font. The atlas rasterizes it with FreeType (the
+    // default loader of the `freetype` build of Dear ImGui, as in Zig) where
+    // that build is available, otherwise with stb_truetype.
+    ctx.font_atlas().add_font(&[embedded_font_source()]);
+}
+
+#[cfg(not(any(windows, target_vendor = "apple", target_arch = "wasm32")))]
+#[allow(unsafe_code)]
+fn embedded_font_source() -> FontSource<'static> {
+    // SAFETY: the embedded font is a complete, valid TrueType font that
+    // lives for the whole program; Dear ImGui copies it on add.
+    unsafe { FontSource::ttf_data_with_size(ghostty_font::embedded::REGULAR, FONT_SIZE) }
+}
+
+#[cfg(any(windows, target_vendor = "apple", target_arch = "wasm32"))]
+fn embedded_font_source() -> FontSource<'static> {
+    match dear_imgui_rs::StbTrueTypeFontData::from_slice(ghostty_font::embedded::REGULAR) {
+        Ok(data) => FontSource::stb_truetype_with_size(data, FONT_SIZE),
+        Err(err) => {
+            log::warn!("failed to load the embedded inspector font err={err}");
+            FontSource::default_font_with_size(FONT_SIZE)
         }
-        Err(err) => log::warn!("failed to load the embedded inspector font err={err}"),
     }
 }
 
@@ -110,6 +125,18 @@ impl InspectorHook for Shared {
 
 #[cfg(test)]
 mod tests {
+    /// Zig sizes the font as `16 * 2` and rasterizes with FreeType.
+    #[test]
+    fn font_size_and_rasterizer_match_zig() {
+        assert!((super::FONT_SIZE - 32.0).abs() < f32::EPSILON);
+        let freetype_target = cfg!(not(any(
+            windows,
+            target_vendor = "apple",
+            target_arch = "wasm32"
+        )));
+        assert_eq!(dear_imgui_rs::HAS_FREETYPE, freetype_target);
+    }
+
     use ghostty_input::{Action, Key, KeyEvent};
     use ghostty_renderer::size::{CellSize, Padding, ScreenSize, Size};
     use ghostty_terminal::terminal::Options;
@@ -146,7 +173,7 @@ mod tests {
     #[test]
     fn draws_frames_headless() {
         let mut ctx = Context::create();
-        setup(&mut ctx, 1.0);
+        setup(&mut ctx);
         ctx.io_mut().set_display_size([1000.0, 700.0]);
         ctx.io_mut().set_delta_time(1.0 / 60.0);
         ctx.font_atlas()

crates/ghostty-inspector/src/widgets/surface.rs

@@ -13,6 +13,10 @@ use super::{key, renderer, terminal, termio};
 use crate::dock::begin_window;
 
 /// This is discovered via the hardcoded string in the ImGui demo window.
+/// True for the Cargo `dev` profile only (Zig `builtin.mode == .Debug`);
+/// set by `build.rs` from `PROFILE`, deliberately not `debug_assertions`.
+pub const DEBUG_BUILD: bool = cfg!(ghostty_debug_build);
+
 const WINDOW_IMGUI_DEMO: &str = "Dear ImGui Demo";
 const WINDOW_KEYBOARD: &str = "Keyboard";
 const WINDOW_TERMINAL: &str = "Terminal";
@@ -133,8 +137,10 @@ impl Inspector {
         crate::dock::flush_splits(ui);
 
         // In debug we show the ImGui demo window so we can easily view
-        // available widgets and such.
-        if cfg!(debug_assertions) && self.show_demo_window {
+        // available widgets and such. Zig checks `builtin.mode == .Debug`
+        // (not `ReleaseSafe`), which is the Cargo `dev` profile; assertions
+        // enabled in a release profile do not count.
+        if DEBUG_BUILD && self.show_demo_window {
             ui.show_demo_window(&mut self.show_demo_window);
         }
 
@@ -399,6 +405,14 @@ fn mouse_button_label(button: usize) -> &'static str {
 mod tests {
     use super::*;
 
+    #[test]
+    fn demo_window_gate_follows_the_dev_profile() {
+        // The `release` profile keeps debug assertions on (like Zig's
+        // ReleaseSafe) but must not show the demo.
+        let debug_build = DEBUG_BUILD;
+        assert_eq!(debug_build, env!("GHOSTTY_BUILD_PROFILE") == "debug");
+    }
+
     #[test]
     fn button_labels() {
         assert_eq!(mouse_button_label(0), "?");

crates/ghostty-inspector/src/widgets/termio.rs

@@ -259,16 +259,20 @@ fn encode_action(md: &mut Vec<(String, String)>, action: &ParserAction) -> Strin
     }
 }
 
-/// Mirrors `Parser.Action.format` for the actions that are not specially
-/// encoded.
+/// Mirrors Zig 0.15.2 `Parser.Action.format` for the actions that are not
+/// specially encoded: `@typeName(Action)`, then `{ .<tag> = <value> }` with
+/// `u8` payloads as `0x{x}` and every other payload printed with
+/// `printValue("any", .., depth 3)`: structs as `.{ .a = .., .b = .. }`,
+/// slices as `{ a, b }` (`{  }` when empty), integers in decimal and `void`
+/// as `void`.
 fn format_action(action: &ParserAction) -> String {
     let (tag, value) = match action {
         ParserAction::DcsHook(d) => (
             "dcs_hook",
             format!(
-                "{{ intermediates = {:?}, params = {:?}, final = {} }}",
-                d.intermediates(),
-                d.params(),
+                ".{{ .intermediates = {}, .params = {}, .final = {} }}",
+                zig_any_slice(d.intermediates()),
+                zig_any_slice(d.params()),
                 d.final_
             ),
         ),
@@ -280,7 +284,21 @@ fn format_action(action: &ParserAction) -> String {
         // Handled by the specific encoders.
         _ => ("unknown", String::new()),
     };
-    format!("parser.Parser.Action{{ .{tag} = {value} }}")
+    format!("terminal.Parser.Action{{ .{tag} = {value} }}")
+}
+
+/// A slice of integers as Zig's `{any}` prints it: `{ 1, 2 }`, or `{  }`
+/// when empty.
+fn zig_any_slice<T: std::fmt::Display>(items: &[T]) -> String {
+    let mut out = String::from("{ ");
+    for (i, v) in items.iter().enumerate() {
+        if i != 0 {
+            out.push_str(", ");
+        }
+        let _ = write!(out, "{v}");
+    }
+    out.push_str(" }");
+    out
 }
 
 fn encode_print(ch: u32) -> String {
@@ -927,6 +945,35 @@ mod tests {
         assert!(filter("-").pass_filter("abc"));
     }
 
+    #[test]
+    fn dcs_and_apc_descriptions_match_zig_format() {
+        // Expected strings produced by Zig 0.15.2 `Parser.Action.format`.
+        let hook = ParserAction::DcsHook(ghostty_vt::parser::Dcs::new(b"$ ", &[1, 2, 300], b'q'));
+        assert_eq!(
+            format_action(&hook),
+            "terminal.Parser.Action{ .dcs_hook = .{ .intermediates = { 36, 32 }, \
+             .params = { 1, 2, 300 }, .final = 113 } }"
+        );
+        let empty = ParserAction::DcsHook(ghostty_vt::parser::Dcs::new(b"", &[], b'q'));
+        assert_eq!(
+            format_action(&empty),
+            "terminal.Parser.Action{ .dcs_hook = .{ .intermediates = {  }, \
+             .params = {  }, .final = 113 } }"
+        );
+        assert_eq!(
+            format_action(&ParserAction::DcsUnhook),
+            "terminal.Parser.Action{ .dcs_unhook = void }"
+        );
+        assert_eq!(
+            format_action(&ParserAction::DcsPut(0x1b)),
+            "terminal.Parser.Action{ .dcs_put = 0x1b }"
+        );
+        assert_eq!(
+            format_action(&ParserAction::ApcPut(0x41)),
+            "terminal.Parser.Action{ .apc_put = 0x41 }"
+        );
+    }
+
     #[test]
     fn encode_execute_names() {
         assert_eq!(encode_execute(0x07), "BEL (0x7)");

crates/ghostty-lib/src/inspector.rs

@@ -54,8 +54,7 @@ impl Inspector {
         }
 
         // Setup our core inspector
-        let scale = f64::from(RtSurface::get_content_scale(surface.as_ref()).x);
-        ghostty_inspector::setup(&mut ctx, scale);
+        ghostty_inspector::setup(&mut ctx);
         if let Err(err) = core.activate_inspector() {
             log::error!("failed to activate inspector err={err}");
         }

docs/rewrite/DEVIANT_FIXES.md

@@ -98,6 +98,7 @@ Only entries with an observable behavioural difference are listed.
 | `+version` / build info | Real build metadata | Placeholder `build_info` values in places; `gtk-opengl-debug` follows `cfg!(debug_assertions)` (the `release` profile has them on, `production` off) | `notes/ghostty-cli.md`, `notes/ghostty-config.md` | 6286e02 |
 | OSC 52 base64 acceptance | Surface.zig:2149,2163 rules | Was different in both directions (Codex core audit); fixed to match Zig | `notes/review-core-codex.md` | 2f58f02 |
 | Benchmark / synthetic tooling extensions | `ghostty-bench` has no `--time` option and only the simplified terminal handler; `ghostty-synthetic` has the actions `ascii`, `osc`, `utf8` | `ghostty-bench --time` prints the measured step time to stderr; `ghostty-bench --handler=full` runs the full `stream_readonly` handler instead of the print-only one; `ghostty-synthetic +sgr` generates SGR-heavy output. Dev/benchmark tooling only; otherwise upstream behaviour is unchanged | `crates/ghostty-bench/src/main.rs`, `src/benches.rs`, `src/bin/ghostty-synthetic.rs`; `notes/review-rv16-codex.md` | 0c4f0ee |
+| Inspector font rasterizer (Windows, Apple, wasm) | Dear ImGui is built with `IMGUI_ENABLE_FREETYPE` (`pkg/dcimgui`), so the 32 px inspector font is rasterized by FreeType | Linux and other Unix targets: FreeType (`dear-imgui-rs` feature `freetype`, system FreeType through pkg-config), 32 px. Windows, Apple and wasm32 keep Dear ImGui's stb_truetype loader at 32 px, because `dear-imgui-sys` can only locate FreeType through pkg-config/vcpkg and those targets cannot be built or run here. Glyph anti-aliasing differs slightly there. | `crates/ghostty-inspector/Cargo.toml`, `src/inspector.rs` (`embedded_font_source`) | Z20 (uncommitted) |
 
 ## Maintenance
 

docs/rewrite/notes/final-Z20.md

@@ -0,0 +1,20 @@
+# Z20: RV17 P3 fixes (uncommitted)
+
+1. FreeType-only on Apple: `ghostty-font/build.rs` honours `font-backend-freetype` on every non-wasm
+   target (`coretext` cfgs off, so the embedded-emoji fallback applies, as in Zig `Discover == void`);
+   `backend.rs` OPTIONS and the `harfbuzz-sys/coretext` feature (now only for the coretext features,
+   because the SDK headers are needed otherwise). New test `selected_backend_matches_build_cfgs`.
+   `ghostty_surface_quicklook_font` now answers only for plain `.coretext` as in Zig
+   (`ghostty_font::face::quicklook_font_raw`). `scripts/macos-crosscheck.sh` takes
+   `MACOS_CHECK_FEATURES`; clippy passes on both Apple targets with and without the feature.
+2. `cli/list_fonts.rs` test follows `ghostty_font::options.backend` / `HAS_DISCOVERY`.
+3. Inspector: 32 px (`FONT_SIZE`), FreeType through `dear-imgui-rs/freetype` on non-Windows, non-Apple,
+   non-wasm targets (registered deviation elsewhere: stb_truetype). `setup` lost its scale parameter
+   (Zig has none). Visual check: new scenario `scripts/visual-parity.sh inspector` (ctrl+shift+i via
+   xdotool, production build vs /usr/bin/ghostty 1.3.1). The window position differs between runs, so the
+   tabs + table region was compared at the best-aligned offset (95,134): 0.031 % of pixels differ
+   (max channel delta 14); the list rows differ only by the hover highlight (pointer position).
+4. DCS/APC descriptions follow Zig 0.15.2 `printValue(any)`; prefix is `terminal.Parser.Action`
+   (was `parser.Parser.Action`), checked by running Zig 0.15.2 (`{ 36, 32 }`, `{  }` for empty slices).
+5. Demo window gate: `ghostty_debug_build` cfg from `PROFILE == "debug"` (`ghostty-inspector/build.rs`).
+6. Metal buffer: `metal_layout::grown_buffer_bytes` + test; DEVIANT_FIXES row 34 (commit bab49ee).

scripts/macos-crosscheck.sh

@@ -3,6 +3,8 @@
 # Uses `zig cc` wrappers for the few C build scripts in the dependency
 # tree; real macOS builds need none of this. See docs/rewrite/notes/macos-M1.md.
 # Usage: scripts/macos-crosscheck.sh [check|clippy] [target]
+# MACOS_CHECK_FEATURES="ghostty-font/font-backend-freetype" adds cargo features
+# (for example the FreeType-only font backend on Apple).
 set -euo pipefail
 cd "$(dirname "$0")/.."
 MODE=${1:-clippy}
@@ -54,8 +56,12 @@ CRATES=(-p ghostty-vt -p ghostty-unicode -p ghostty-datastruct -p ghostty-os -p
   -p ghostty-config -p ghostty-terminal -p ghostty-font -p ghostty-renderer -p ghostty-termio
   -p ghostty-core -p ghostty-apprt -p ghostty-inspector -p ghostty-lib -p ghostty-crash
   -p ghostty-bench -p ghostty-vt-capi)
+FEATURES=()
+if [ -n "${MACOS_CHECK_FEATURES:-}" ]; then
+  FEATURES=(--features "$MACOS_CHECK_FEATURES")
+fi
 if [ "$MODE" = clippy ]; then
-  cargo clippy --target "$TARGET" "${CRATES[@]}" --lib --tests -- -D warnings
+  cargo clippy --target "$TARGET" "${CRATES[@]}" "${FEATURES[@]}" --lib --tests -- -D warnings
 else
-  cargo check --target "$TARGET" "${CRATES[@]}" --lib --tests
+  cargo check --target "$TARGET" "${CRATES[@]}" "${FEATURES[@]}" --lib --tests
 fi

scripts/visual-parity.sh

@@ -2,7 +2,8 @@
 # Visual parity: capture original Ghostty and the Rust build in an isolated,
 # headless nested weston and compare pixel-wise.
 #
-#   scripts/visual-parity.sh [scenario...]     (default: page page-bar tabs)
+#   scripts/visual-parity.sh [scenario...]     (default: page page-bar tabs;
+#   also available: inspector = ctrl+shift+i via xdotool)
 #
 # env: RUST_BIN (default target/production/ghostty), REF_BIN (default
 # /usr/bin/ghostty), OUT (default target/visual-parity), W/H output size.
@@ -22,7 +23,7 @@ WORK=$(mktemp -d "$OUT/work.XXXX")
 SOCK=vp$$
 
 XWL=
-case " $SCEN " in *" tabs "*) XWL=xwayland=true; mkdir -p /tmp/.X11-unix ;; esac
+case " $SCEN " in *" tabs "*|*" inspector "*) XWL=xwayland=true; mkdir -p /tmp/.X11-unix ;; esac
 cat >"$WORK/weston.ini" <<INI
 [core]
 shell=desktop-shell.so
@@ -80,7 +81,7 @@ run_one() {
     HOME=$WORK/home-$label)
   mkdir -p "$WORK/home-$label"
   case $scen in
-  tabs)
+  tabs|inspector)
     # Needs input: run under Xwayland and drive with xdotool.
     env=("${env[@]/GDK_BACKEND=wayland/GDK_BACKEND=x11}")
     env+=(DISPLAY="$(xwl_display)")
@@ -88,7 +89,7 @@ run_one() {
       -e "$VP/testpage.sh" >"$WORK/$label-$scen.log" 2>&1 &
     local pid=$!
     sleep 6
-    xdotool_keys
+    xdotool_keys "$scen"
     sleep 3
     shoot "$out"
     kill $pid 2>/dev/null; wait $pid 2>/dev/null
@@ -106,6 +107,10 @@ run_one() {
 xwl_display() { grep -o "display :[0-9]*" "$WORK/weston.log" | tail -1 | sed 's/display //'; }
 xdotool_keys() {
   export DISPLAY=$(xwl_display)
+  if [ "${1:-}" = inspector ]; then
+    xdotool key --clearmodifiers ctrl+shift+i; sleep 3
+    return
+  fi
   xdotool key --clearmodifiers ctrl+shift+t; sleep 1
   xdotool key --clearmodifiers ctrl+shift+o; sleep 1
   xdotool key --clearmodifiers ctrl+shift+e; sleep 1