From c546442b4f8f7de4a2253d3fe9426ce3b8f63f48 Mon Sep 17 00:00:00 2001
From: minhn4 <nguyenm.cuny@gmail.com>
Date: Fri, 25 Sep 2026 17:33:26 +0700
Subject: [PATCH] fix(sandbox): build the universal VM helper on Command Line
 Tools 27
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Release packaging (desktop prebuild → build-vzhelper.ts --universal)
failed on Command Line Tools 27 / Swift 6.4: the helper's macOS 12
deployment target links Swift's back-compatibility libraries
(libswiftCompatibility56, libswiftCompatibilityPacks), and this toolchain
ships every one of them for arm64/arm64e only, so the x86_64 slice failed
to link ("fat file missing arch 'x86_64'", undefined symbols). macOS
releases had to be built by hand.

When the toolchain's libswiftCompatibility56.a has no x86_64 slice, the
Intel slice is now built with `-runtime-compatibility-version none`. The
arm64 slice keeps the libraries, and a toolchain that still ships Intel
copies keeps them for Intel too; the only cost is Intel Macs on macOS
12.0–12.2 running the helper without those runtime fixes.

Also quiets the failed first attempt on the default build system before
the `--build-system native` retry (#380), so a successful build no longer
logs a wall of errors.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 .../codev-sandbox/script/build-vzhelper.ts    | 31 +++++++++++++++----
 1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/packages/codev-sandbox/script/build-vzhelper.ts b/packages/codev-sandbox/script/build-vzhelper.ts
index 273f9cedd..94b0af679 100644
--- a/packages/codev-sandbox/script/build-vzhelper.ts
+++ b/packages/codev-sandbox/script/build-vzhelper.ts
@@ -7,6 +7,7 @@
 // build to xcbuild, which only full Xcode ships — Command Line Tools setups
 // error with "xcbuild executable ... does not exist".
 import { $ } from "bun"
+import { dirname, join } from "node:path"
 import { fileURLToPath } from "node:url"
 
 const root = fileURLToPath(new URL("../native/vzhelper/", import.meta.url))
@@ -17,11 +18,9 @@ const slices = await (async () => {
     await swiftBuild([])
     return [`${root}.build/release/codev-vmm`]
   }
-  const triples = ["arm64-apple-macosx", "x86_64-apple-macosx"]
-  for (const triple of triples) {
-    await swiftBuild(["--triple", triple])
-  }
-  return triples.map((triple) => `${root}.build/${triple}/release/codev-vmm`)
+  await swiftBuild(["--triple", "arm64-apple-macosx"])
+  await swiftBuild(["--triple", "x86_64-apple-macosx", ...(await intelCompatibilityFlags())])
+  return ["arm64-apple-macosx", "x86_64-apple-macosx"].map((triple) => `${root}.build/${triple}/release/codev-vmm`)
 })()
 
 await $`mkdir -p ${root}dist`
@@ -40,8 +39,28 @@ console.log(`built ${root}dist/codev-vmm${universal ? " (universal)" : ""}`)
 // first attempt in case a later Swift drops it.
 async function swiftBuild(extra: string[]) {
   const args = ["build", "-c", "release", "--package-path", root, ...extra]
-  const first = await $`swift ${args}`.nothrow()
+  // Quiet: on the toolchains this exists for, the default backend's failure
+  // is a wall of expected noise. The retry's own error still prints.
+  const first = await $`swift ${args}`.nothrow().quiet()
   if (first.exitCode === 0) return
   console.warn("swift build failed with the default build system; retrying with --build-system native")
   await $`swift ${args} --build-system native`
 }
+
+// A macOS 12 deployment target links Swift's back-compatibility libraries
+// (libswiftCompatibility56 for macOS 12.0–12.2, libswiftCompatibilityPacks),
+// and Command Line Tools 27 ships them for arm64/arm64e only — the x86_64
+// link fails with "fat file missing arch 'x86_64'" and undefined symbols.
+// When the toolchain lacks the Intel copies, the Intel slice is built
+// without them instead. The cost is confined to Intel Macs still on macOS
+// 12.0–12.2, which run the helper without those runtime fixes; Apple Silicon
+// keeps them, and a toolchain that still has Intel copies keeps them for
+// Intel too.
+async function intelCompatibilityFlags(): Promise<string[]> {
+  const swift = (await $`xcrun --find swift`.text()).trim()
+  const library = join(dirname(dirname(swift)), "lib", "swift", "macosx", "libswiftCompatibility56.a")
+  const archs = await $`lipo -archs ${library}`.nothrow().quiet().text()
+  if (archs.split(/\s+/).includes("x86_64")) return []
+  console.warn("this Swift toolchain has no x86_64 compatibility libraries; building the Intel slice without them")
+  return ["-Xswiftc", "-runtime-compatibility-version", "-Xswiftc", "none"]
+}