feat(next-swc): report native bindings load err code (#52570)

Related: vercel/next-telemetry#106

We collect wasm fallback reason (`enabled`, `fallback`, ..) but it is bit unclear why we came to reach `fallback` state for the wasm. This PR expands current reporting to include native bindings error code if node.js returns it to understand categories better. Mostly this would be in between ERR_DLOPEN or ERR_MODULE_NOT_FOUND, but worth to confirm if the guess is correct. For the targets have multiple triples (gnu / musl), we collect only the last attempt's error code.

There are 2 custom variants of the string value other than err code itself: if thrown error doesn't have code (unlikely, but) it'll be `unknown`. for the targets we falls back to wasm immediately (freebsd, for example) it'll be marked as unsupported_target.

One thing to note is this does not collect if wasm binding fails to load: this is strictly for native bindings load error.

packages/next/src/build/swc/index.ts

@@ -71,6 +71,14 @@ const knownDefaultWasmFallbackTriples = [
   'i686-pc-windows-msvc',
 ]
 
+// The last attempt's error code returned when cjs require to native bindings fails.
+// If node.js throws an error without error code, this should be `unknown` instead of undefined.
+// For the wasm-first targets (`knownDefaultWasmFallbackTriples`) this will be `unsupported_target`.
+let lastNativeBindingsLoadErrorCode:
+  | 'unknown'
+  | 'unsupported_target'
+  | string
+  | undefined = undefined
 let nativeBindings: any
 let wasmBindings: any
 let downloadWasmPromise: any
@@ -104,6 +112,7 @@ export async function loadBindings(): Promise<any> {
       )
 
     if (shouldLoadWasmFallbackFirst) {
+      lastNativeBindingsLoadErrorCode = 'unsupported_target'
       const fallbackBindings = await tryLoadWasmWithFallback(
         attempts,
         isCustomTurbopack
@@ -142,7 +151,10 @@ async function tryLoadWasmWithFallback(
   try {
     let bindings = await loadWasm('', isCustomTurbopack)
     // @ts-expect-error TODO: this event has a wrong type.
-    eventSwcLoadFailure({ wasm: 'enabled' })
+    eventSwcLoadFailure({
+      wasm: 'enabled',
+      nativeBindingsErrorCode: lastNativeBindingsLoadErrorCode,
+    })
     return bindings
   } catch (a) {
     attempts = attempts.concat(a)
@@ -166,7 +178,10 @@ async function tryLoadWasmWithFallback(
       isCustomTurbopack
     )
     // @ts-expect-error TODO: this event has a wrong type.
-    eventSwcLoadFailure({ wasm: 'fallback' })
+    eventSwcLoadFailure({
+      wasm: 'fallback',
+      nativeBindingsErrorCode: lastNativeBindingsLoadErrorCode,
+    })
 
     // still log native load attempts so user is
     // aware it failed and should be fixed
@@ -208,7 +223,10 @@ function logLoadFailure(attempts: any, triedWasm = false) {
   }
 
   // @ts-expect-error TODO: this event has a wrong type.
-  eventSwcLoadFailure({ wasm: triedWasm ? 'failed' : undefined })
+  eventSwcLoadFailure({
+    wasm: triedWasm ? 'failed' : undefined,
+    nativeBindingsErrorCode: lastNativeBindingsLoadErrorCode,
+  })
     .then(() => lockfilePatchPromise.cur || Promise.resolve())
     .finally(() => {
       Log.error(
@@ -386,6 +404,7 @@ function loadNative(isCustomTurbopack = false) {
             `Attempted to load ${pkg}, but an error occurred: ${e.message ?? e}`
           )
         }
+        lastNativeBindingsLoadErrorCode = e?.code ?? 'unknown'
       }
     }
   }

packages/next/src/telemetry/events/swc-load-failure.ts

@@ -14,6 +14,7 @@ export type EventSwcLoadFailure = {
     wasm?: 'enabled' | 'fallback' | 'failed'
     glibcVersion?: string
     installedSwcPackages?: string
+    nativeBindingsErrorCode?: string
   }
 }
 
@@ -60,6 +61,7 @@ export async function eventSwcLoadFailure(
       platform: process.platform,
       nodeVersion: process.versions.node,
       wasm: event?.wasm,
+      nativeBindingsErrorCode: event?.nativeBindingsErrorCode,
     },
   })
   // ensure this event is flushed before process exits