Update to Zig 0.16.0

This commit represents the majority of the work necessary to upgrade
Ghostty to use Zig 0.16.0.

At this point, the project builds, tests, and runs under Linux. More
work may be necessary for other platforms, and possibly to fix any
(currently unknown) upgrade regressions.

Co-authored-by: Leah Amelia Chen <hi@pluie.me>

Author: vancluever

.clang-format

@@ -179,4 +179,3 @@ WhitespaceSensitiveMacros:
   - PP_STRINGIZE
   - BOOST_PP_STRINGIZE
 ---
-

.github/workflows/test.yml

@@ -1196,9 +1196,29 @@ jobs:
       - name: Test GTK Build
         run: nix develop -c zig build -Dapp-runtime=gtk -Demit-docs -Demit-webdata
 
-      # This relies on the cache being populated by the commands above.
+        # NOTE: This used to point to the Zig global cache directory before
+        # 0.16.0. Now, the cache directory exclusively stores "minified"
+        # archives of each dependency (i.e., only the paths defined in
+        # build.zig.zon), and an uncompressed, working copy is stored in
+        # PROJECT_ROOT/zig-pkg. The zig-pkg directory is warmed up during the
+        # regular fetching process from the global cache directory if
+        # possible.
+        #
+        # Nothing else should change; zon2nix's store path mimics what a
+        # zig-pkg directory should look like, so actual build steps should be
+        # fine, it's just here where we assume that all dependencies have been
+        # downloaded, and we want to test the validity of the package
+        # directory, do we need to have it pointing to zig-pkg and not the
+        # zon2nix store path.
+        #
+        # Note that this can also be attempted by running:
+        #   zig build --fetch=needed
+        #
+        # Note that --system PKGDIR should not be added to this invocation as
+        # it disables fetching altogether (even, seemingly, from the local
+        # cache).
       - name: Test System Build
-        run: nix develop -c zig build --system ${ZIG_GLOBAL_CACHE_DIR}/p
+        run: nix develop -c zig build --system "$(realpath zig-pkg)"
 
   test-lib-vt:
     if: github.repository == 'ghostty-org/ghostty' && needs.skip.outputs.skip != 'true'

.gitignore

@@ -10,6 +10,7 @@
 zig-cache/
 .zig-cache/
 zig-out/
+zig-pkg/
 build-cmake/
 CMakeCache.txt
 CMakeFiles/
@@ -29,3 +30,4 @@ glad.zip
 
 vgcore.*
 
+/sprite_face_test*

build.zig

@@ -25,9 +25,10 @@ pub fn build(b: *std.Build) !void {
     // use that as the version source of truth. Otherwise we fall back
     // to what is in the build.zig.zon.
     const file_version: ?[]const u8 = if (b.build_root.handle.readFileAlloc(
-        b.allocator,
+        b.graph.io,
         "VERSION",
-        128,
+        b.allocator,
+        .limited(128),
     )) |content| std.mem.trim(
         u8,
         content,
@@ -298,7 +299,7 @@ pub fn build(b: *std.Build) !void {
         // We need to rebuild Ghostty with a baseline CPU target.
         const valgrind_exe = exe: {
             var valgrind_config = config;
-            valgrind_config.target = valgrind_config.baselineTarget();
+            valgrind_config.target = valgrind_config.baselineTarget(b.graph.io);
             break :exe try buildpkg.GhosttyExe.init(
                 b,
                 &valgrind_config,
@@ -343,7 +344,7 @@ pub fn build(b: *std.Build) !void {
             .filters = test_filters,
             .root_module = b.createModule(.{
                 .root_source_file = b.path("src/main.zig"),
-                .target = config.baselineTarget(),
+                .target = config.baselineTarget(b.graph.io),
                 .optimize = .Debug,
                 .strip = false,
                 .omit_frame_pointer = false,
@@ -358,7 +359,7 @@ pub fn build(b: *std.Build) !void {
         // Verify our internal libghostty header.
         const ghostty_h = b.addTranslateC(.{
             .root_source_file = b.path("include/ghostty.h"),
-            .target = config.baselineTarget(),
+            .target = config.baselineTarget(b.graph.io),
             .optimize = .Debug,
         });
         test_exe.root_module.addImport("ghostty.h", ghostty_h.createModule());

build.zig.zon

@@ -3,62 +3,71 @@
     .version = "1.3.2-dev",
     .paths = .{""},
     .fingerprint = 0x64407a2a0b4147e5,
-    .minimum_zig_version = "0.15.2",
+    .minimum_zig_version = "0.16.0",
     .dependencies = .{
-        // Zig libs
+        // External translate-c
+        // NOTE: We might not need to keep this around forever, but we need it
+        // for at least the 0.16.0 release cycle since we need fixes in
+        // Aro/translate-c itself.
+        .translate_c = .{
+            .lazy = true,
+            .url = "https://codeberg.org/vancluever/translate-c/archive/a5bc193c925b03f74d44e1a4b29c117822473b91.tar.gz",
+            .hash = "translate_c-0.0.0-Q_BUWhFXBwBZBr7EnRC97AKPYXbwHkpcc4TASklMqZu9",
+        },
 
+        // Zig libs
         .libxev = .{
             // mitchellh/libxev
-            .url = "https://deps.files.ghostty.org/libxev-34fa50878aec6e5fa8f532867001ab3c36fae23e.tar.gz",
-            .hash = "libxev-0.0.0-86vtc4IcEwCqEYxEYoN_3KXmc6A9VLcm22aVImfvecYs",
+            .url = "https://github.com/mitchellh/libxev/archive/9ce8e8e6ff89e583258a7f8e7adeeeaeae8611bf.tar.gz",
+            .hash = "libxev-0.0.0-86vtcwIRFADbH4hk-EjROXxlrKIRPQdA41XiTSytYO-F",
             .lazy = true,
         },
         .vaxis = .{
             // rockorager/libvaxis
-            .url = "https://deps.files.ghostty.org/vaxis-7dbb9fd3122e4ffad262dd7c151d80d863b68558.tar.gz",
-            .hash = "vaxis-0.5.1-BWNV_LosCQAGmCCNOLljCIw6j6-yt53tji6n6rwJ2BhS",
+            .url = "https://github.com/rockorager/libvaxis/archive/1dbbe575dff4586fe51e3217aa5c3fecdcbb6089.tar.gz",
+            .hash = "vaxis-0.6.0-BWNV_CrbCQCscGpzsAlR402rYQ_tV3aAl081c2iRRkka",
             .lazy = true,
         },
         .z2d = .{
             // vancluever/z2d
-            .url = "https://deps.files.ghostty.org/z2d-0.10.0-j5P_Hu-6FgBsZNgwphIqh17jDnj8_yPtD8yzjO6PpHRQ.tar.gz",
-            .hash = "z2d-0.10.0-j5P_Hu-6FgBsZNgwphIqh17jDnj8_yPtD8yzjO6PpHRQ",
+            .url = "https://github.com/vancluever/z2d/archive/refs/tags/v0.11.0.tar.gz",
+            .hash = "z2d-0.11.0-j5P_HtLzDwBGyQt49DrT0v4BuVqI_SRs6CXsuj7eBVhR",
             .lazy = true,
         },
         .zig_objc = .{
             // mitchellh/zig-objc
-            .url = "https://deps.files.ghostty.org/zig_objc-f356ed02833f0f1b8e84d50bed9e807bf7cdc0ae.tar.gz",
-            .hash = "zig_objc-0.0.0-Ir_Sp5gTAQCvxxR7oVIrPXxXwsfKgVP7_wqoOQrZjFeK",
+            .url = "https://github.com/mitchellh/zig-objc/archive/c8de82ff80281215ad92900866dab7103a8efa8b.tar.gz",
+            .hash = "zig_objc-0.0.0-Ir_Sp9gsAQCPAJc0oF5xoWePHWP6Y6tCphDeyNUThJoi",
             .lazy = true,
         },
         .zig_js = .{
             // mitchellh/zig-js
-            .url = "https://deps.files.ghostty.org/zig_js-04db83c617da1956ac5adc1cb9ba1e434c1cb6fd.tar.gz",
-            .hash = "zig_js-0.0.0-rjCAV-6GAADxFug7rDmPH-uM_XcnJ5NmuAMJCAscMjhi",
+            .url = "https://github.com/mitchellh/zig-js/archive/3c23860e47fdcdc5af805efb7fd0bdac5fd3e9bc.tar.gz",
+            .hash = "zig_js-0.0.0-rjCAV7-GAADvMTBL7lPMuvDk7xgS9PCMIZWiOUXLZSlj",
             .lazy = true,
         },
         .uucode = .{
             // jacobsandlund/uucode
-            .url = "https://deps.files.ghostty.org/uucode-0.2.0-ZZjBPqZVVABQepOqZHR7vV_NcaN-wats0IB6o-Exj6m9.tar.gz",
-            .hash = "uucode-0.2.0-ZZjBPqZVVABQepOqZHR7vV_NcaN-wats0IB6o-Exj6m9",
+            .url = "https://github.com/jacobsandlund/uucode/archive/2826a37a4562284fdacd8fa029d49509cc9bffcd.tar.gz",
+            .hash = "uucode-0.2.0-ZZjBPlK5VADj7fdoq7G8LIHzD5o6FSkcBXXrRWr4jnrA",
         },
         .zig_wayland = .{
             // codeberg ifreund/zig-wayland
-            .url = "https://deps.files.ghostty.org/zig_wayland-1b5c038ec10da20ed3a15b0b2a6db1c21383e8ea.tar.gz",
-            .hash = "wayland-0.5.0-dev-lQa1khrMAQDJDwYFKpdH3HizherB7sHo5dKMECfvxQHe",
+            .url = "https://codeberg.org/ifreund/zig-wayland/archive/v0.6.0.tar.gz",
+            .hash = "wayland-0.6.0-lQa1kqz8AQADQmdNJsNhLoNHcnEGEUjrOaPV-dtEnEmX",
             .lazy = true,
         },
         .zf = .{
             // natecraddock/zf
-            .url = "https://deps.files.ghostty.org/zf-3c52637b7e937c5ae61fd679717da3e276765b23.tar.gz",
-            .hash = "zf-0.10.3-OIRy8RuJAACKA3Lohoumrt85nRbHwbpMcUaLES8vxDnh",
+            .url = "https://github.com/natecraddock/zf/archive/c35c421f84895193246db06c40683c1a30e616ef.tar.gz",
+            .hash = "zf-0.11.0-OIRy8X-RAAAwaRXHMYpj2uvBnuGTZWEE_3V7acqHQNtW",
             .lazy = true,
         },
         .gobject = .{
             // https://github.com/ghostty-org/zig-gobject based on zig_gobject
             // Temporary until we generate them at build time automatically.
-            .url = "https://deps.files.ghostty.org/gobject-2025-11-08-23-1.tar.zst",
-            .hash = "gobject-0.3.0-Skun7ANLnwDvEfIpVmohcppXgOvg_I6YOJFmPIsKfXk-",
+            .url = "https://github.com/ghostty-org/zig-gobject/releases/download/0.8.0-2026-04-23-26-1/ghostty-gobject-0.8.0-2026-04-23-26-1.tar.zst",
+            .hash = "gobject-0.3.1-Skun7E1KnwBGMX5nslHYG1yWHaSevywxQO8oM7tTOgIp",
             .lazy = true,
         },