replace @Panic with b.addFail in standalone test build.zig

Author: dasimmet

test/standalone/ios/build.zig

@@ -12,9 +12,6 @@ pub fn build(b: *std.Build) void {
         .cpu_arch = .aarch64,
         .os_tag = .ios,
     });
-    const sdk = std.zig.system.darwin.getSdk(b.allocator, &target.result) orelse
-        @panic("no iOS SDK found");
-    b.sysroot = sdk;
 
     const exe = b.addExecutable(.{
         .name = "main",
@@ -25,10 +22,17 @@ pub fn build(b: *std.Build) void {
             .link_libc = true,
         }),
     });
+
+    if (std.zig.system.darwin.getSdk(b.allocator, &target.result)) |sdk| {
+        b.sysroot = sdk;
+        exe.root_module.addSystemIncludePath(.{ .cwd_relative = b.pathJoin(&.{ sdk, "/usr/include" }) });
+        exe.root_module.addSystemFrameworkPath(.{ .cwd_relative = b.pathJoin(&.{ sdk, "/System/Library/Frameworks" }) });
+        exe.root_module.addLibraryPath(.{ .cwd_relative = b.pathJoin(&.{ sdk, "/usr/lib" }) });
+    } else {
+        exe.step.dependOn(&b.addFail("no iOS SDK found").step);
+    }
+
     exe.root_module.addCSourceFile(.{ .file = b.path("main.m"), .flags = &.{} });
-    exe.root_module.addSystemIncludePath(.{ .cwd_relative = b.pathJoin(&.{ sdk, "/usr/include" }) });
-    exe.root_module.addSystemFrameworkPath(.{ .cwd_relative = b.pathJoin(&.{ sdk, "/System/Library/Frameworks" }) });
-    exe.root_module.addLibraryPath(.{ .cwd_relative = b.pathJoin(&.{ sdk, "/usr/lib" }) });
     exe.root_module.linkFramework("Foundation", .{});
     exe.root_module.linkFramework("UIKit", .{});