build: zig build run only builds xcframework for current arch

build.zig

@@ -95,7 +95,11 @@ pub fn build(b: *std.Build) !void {
         if (!config.emit_xcframework) break :none;
 
         // Build the xcframework
-        const xcframework = try buildpkg.GhosttyXCFramework.init(b, &deps);
+        const xcframework = try buildpkg.GhosttyXCFramework.init(
+            b,
+            &deps,
+            .universal,
+        );
         xcframework.install();
 
         // The xcframework build always installs resources because our
@@ -113,16 +117,24 @@ pub fn build(b: *std.Build) !void {
         }
 
         // Build our macOS app
+        {
+            const xcframework_native = try buildpkg.GhosttyXCFramework.init(
+                b,
+                &deps,
+                .native,
+            );
+
             const app = try buildpkg.GhosttyXcodebuild.init(
                 b,
                 &config,
-            &xcframework,
+                &xcframework_native,
             );
 
             // Add a run command that opens our mac app.
             const run_step = b.step("run", "Run the app");
             run_step.dependOn(&app.open.step);
         }
+    }
 
     // Tests
     {

src/build/GhosttyXCFramework.zig

@@ -7,11 +7,23 @@ const GhosttyLib = @import("GhosttyLib.zig");
 const XCFrameworkStep = @import("XCFrameworkStep.zig");
 
 xcframework: *XCFrameworkStep,
-macos: GhosttyLib,
+target: Target,
 
-pub fn init(b: *std.Build, deps: *const SharedDeps) !GhosttyXCFramework {
-    // Create our universal macOS static library.
-    const macos = try GhosttyLib.initMacOSUniversal(b, deps);
+pub const Target = enum { native, universal };
+
+pub fn init(
+    b: *std.Build,
+    deps: *const SharedDeps,
+    target: Target,
+) !GhosttyXCFramework {
+    // Universal macOS build
+    const macos_universal = try GhosttyLib.initMacOSUniversal(b, deps);
+
+    // Native macOS build
+    const macos_native = try GhosttyLib.initStatic(b, &try deps.retarget(
+        b,
+        Config.genericMacOSTarget(b, null),
+    ));
 
     // iOS
     const ios = try GhosttyLib.initStatic(b, &try deps.retarget(
@@ -47,9 +59,10 @@ pub fn init(b: *std.Build, deps: *const SharedDeps) !GhosttyXCFramework {
     const xcframework = XCFrameworkStep.create(b, .{
         .name = "GhosttyKit",
         .out_path = "macos/GhosttyKit.xcframework",
-        .libraries = &.{
+        .libraries = switch (target) {
+            .universal => &.{
                 .{
-                .library = macos.output,
+                    .library = macos_universal.output,
                     .headers = b.path("include"),
                 },
                 .{
@@ -61,11 +74,17 @@ pub fn init(b: *std.Build, deps: *const SharedDeps) !GhosttyXCFramework {
                     .headers = b.path("include"),
                 },
             },
+
+            .native => &.{.{
+                .library = macos_native.output,
+                .headers = b.path("include"),
+            }},
+        },
     });
 
     return .{
         .xcframework = xcframework,
-        .macos = macos,
+        .target = target,
     };
 }
 

src/build/GhosttyXcodebuild.zig

@@ -1,6 +1,7 @@
 const Ghostty = @This();
 
 const std = @import("std");
+const builtin = @import("builtin");
 const RunStep = std.Build.Step.Run;
 const Config = @import("Config.zig");
 const XCFramework = @import("GhosttyXCFramework.zig");
@@ -40,6 +41,23 @@ pub fn init(
             xc_config,
         });
 
+        switch (xcframework.target) {
+            // Universal is our default target, so we don't have to
+            // add anything.
+            .universal => {},
+
+            // Native we need to override the architecture in the Xcode
+            // project with the -arch flag.
+            .native => build.addArgs(&.{
+                "-arch",
+                switch (builtin.cpu.arch) {
+                    .aarch64 => "arm64",
+                    .x86_64 => "x86_64",
+                    else => @panic("unsupported macOS arch"),
+                },
+            }),
+        }
+
         // We need the xcframework
         build.step.dependOn(xcframework.xcframework.step);