fix: enhance cross-compilation process by replacing native binaries post-rebuild

forge.config.ts

@@ -68,73 +68,7 @@ const config: ForgeConfig = {
         env: { ...process.env, npm_config_nodedir: '' },
       });
 
-      // When cross-compiling, native addons (better-sqlite3) are built
-      // for the build machine (Linux). Use @electron/rebuild to get the
-      // correct binaries for the target platform.
       const targetKey = `${platform}-${arch}`;
-      const buildKey = `${process.platform}-${process.arch}`;
-      if (targetKey !== buildKey) {
-        console.log(`[forge] Cross-compiling: ${buildKey} → ${targetKey}`);
-        const electronVersion = JSON.parse(
-          fs.readFileSync(path.resolve(__dirname, 'node_modules', 'electron', 'package.json'), 'utf-8'),
-        ).version;
-
-        // Rebuild native modules for target platform using prebuild-install.
-        // prebuild-install supports cross-platform via --platform/--arch,
-        // unlike @electron/rebuild which only supports --arch.
-        // This is FATAL — a Linux .node in a Windows package is always broken.
-        const nativeModules = ['better-sqlite3'];
-        for (const mod of nativeModules) {
-          const modDir = path.join(buildPath, 'node_modules', mod);
-          if (!fs.existsSync(modDir)) continue;
-
-          // Clean stale build artifacts — a leftover build/Release/*.node
-          // for the host platform must not survive.
-          const buildRelease = path.join(modDir, 'build', 'Release');
-          if (fs.existsSync(buildRelease)) {
-            fs.rmSync(buildRelease, { recursive: true, force: true });
-            console.log(`[forge] Cleaned stale build/Release for ${mod}`);
-          }
-
-          console.log(`[forge] Downloading ${mod} prebuilt for ${targetKey} (Electron ${electronVersion})...`);
-          execSync(
-            `npx --yes prebuild-install -r electron -t ${electronVersion} ` +
-            `--platform ${platform} --arch ${arch} --tag-prefix v --verbose`,
-            { cwd: modDir, stdio: 'inherit' },
-          );
-
-          // prebuild-install writes the binary to build/Release/<name>.node.
-          // Verify at least one .node file exists there and is NOT an ELF
-          // (Linux) binary — a Linux .node in a Windows package always crashes.
-          const releaseDir = path.join(modDir, 'build', 'Release');
-          if (!fs.existsSync(releaseDir)) {
-            throw new Error(
-              `[forge] FATAL: build/Release/ not found for ${mod} after prebuild-install. ` +
-              `The native binary was not downloaded.`,
-            );
-          }
-          const nodeFiles = fs.readdirSync(releaseDir).filter((f) => f.endsWith('.node'));
-          if (nodeFiles.length === 0) {
-            throw new Error(
-              `[forge] FATAL: No .node files in build/Release/ for ${mod} after prebuild-install.`,
-            );
-          }
-          for (const f of nodeFiles) {
-            const buf = Buffer.alloc(4);
-            const fd = fs.openSync(path.join(releaseDir, f), 'r');
-            fs.readSync(fd, buf, 0, 4, 0);
-            fs.closeSync(fd);
-            // ELF magic: 0x7f 'E' 'L' 'F'
-            if (buf[0] === 0x7f && buf[1] === 0x45 && buf[2] === 0x4c && buf[3] === 0x46) {
-              throw new Error(
-                `[forge] FATAL: ${mod} build/Release/${f} is an ELF binary! ` +
-                `Cross-compilation failed — refusing to package a Linux .node for Windows.`,
-              );
-            }
-            console.log(`[forge] Verified ${f} is not ELF ✓`);
-          }
-        }
-      }
 
       // vectordb uses platform-specific optional deps (@lancedb/vectordb-<platform>-<arch>-*).
       // npm install on Linux only pulls the Linux variant. Force-install the target's.
@@ -224,6 +158,80 @@ const config: ForgeConfig = {
         }
       }
     },
+
+    // ── Post-rebuild: fix native binaries for cross-compilation ──────
+    // Forge runs @electron/rebuild AFTER packageAfterCopy, which
+    // recompiles native addons for the BUILD platform (Linux).
+    // packageAfterPrune runs AFTER rebuild+prune, so we can safely
+    // replace the Linux .node files with the correct target prebuilts.
+    packageAfterPrune: async (_forgeConfig, buildPath, _electronVersion, platform, arch) => {
+      const targetKey = `${platform}-${arch}`;
+      const buildKey = `${process.platform}-${process.arch}`;
+      if (targetKey === buildKey) return; // native build — nothing to fix
+
+      console.log(`[forge:afterPrune] Cross-compile fixup: ${buildKey} → ${targetKey}`);
+      const electronVersion = JSON.parse(
+        fs.readFileSync(path.resolve(__dirname, 'node_modules', 'electron', 'package.json'), 'utf-8'),
+      ).version;
+
+      // Replace native addons that @electron/rebuild compiled for the host.
+      const nativeModules = ['better-sqlite3'];
+      for (const mod of nativeModules) {
+        const modDir = path.join(buildPath, 'node_modules', mod);
+        if (!fs.existsSync(modDir)) continue;
+
+        // Remove the host-platform binary left by @electron/rebuild
+        const buildRelease = path.join(modDir, 'build', 'Release');
+        if (fs.existsSync(buildRelease)) {
+          fs.rmSync(buildRelease, { recursive: true, force: true });
+          console.log(`[forge:afterPrune] Cleaned host-platform build/Release for ${mod}`);
+        }
+
+        // Download the correct prebuilt for the TARGET platform
+        console.log(`[forge:afterPrune] Downloading ${mod} prebuilt for ${targetKey} (Electron ${electronVersion})...`);
+        execSync(
+          `npx --yes prebuild-install -r electron -t ${electronVersion} ` +
+          `--platform ${platform} --arch ${arch} --tag-prefix v --verbose`,
+          { cwd: modDir, stdio: 'inherit' },
+        );
+
+        // Verify the binary exists and is for the correct platform.
+        const releaseDir = path.join(modDir, 'build', 'Release');
+        if (!fs.existsSync(releaseDir)) {
+          throw new Error(
+            `[forge] FATAL: build/Release/ not found for ${mod} after prebuild-install. ` +
+            `The native binary was not downloaded.`,
+          );
+        }
+        const nodeFiles = fs.readdirSync(releaseDir).filter((f) => f.endsWith('.node'));
+        if (nodeFiles.length === 0) {
+          throw new Error(
+            `[forge] FATAL: No .node files in build/Release/ for ${mod} after prebuild-install.`,
+          );
+        }
+        for (const f of nodeFiles) {
+          const buf = Buffer.alloc(4);
+          const fd = fs.openSync(path.join(releaseDir, f), 'r');
+          fs.readSync(fd, buf, 0, 4, 0);
+          fs.closeSync(fd);
+          // ELF magic: 0x7f 'E' 'L' 'F'
+          if (buf[0] === 0x7f && buf[1] === 0x45 && buf[2] === 0x4c && buf[3] === 0x46) {
+            throw new Error(
+              `[forge] FATAL: ${mod} build/Release/${f} is an ELF binary! ` +
+              `Cross-compilation failed — refusing to package a Linux .node for Windows.`,
+            );
+          }
+          // PE magic: 'M' 'Z' (0x4d 0x5a) — expected for win32
+          if (platform === 'win32' && !(buf[0] === 0x4d && buf[1] === 0x5a)) {
+            throw new Error(
+              `[forge] FATAL: ${mod} build/Release/${f} is not a PE (Windows) binary! ` +
+              `Magic bytes: ${buf.toString('hex')}. Refusing to package.`,
+            );
+          }
+          console.log(`[forge:afterPrune] Verified ${mod}/${f} — correct platform ✓`);
+        }
+      }
+    },
   },
   makers: [
     new MakerSquirrel({}),