Apply segfault workaround to image optimizer as well

packages/optimizers/image/package.json

@@ -35,6 +35,7 @@
     "@parcel/diagnostic": "^2.0.1",
     "@parcel/plugin": "^2.0.1",
     "@parcel/utils": "^2.0.1",
+    "@parcel/workers": "^2.0.1",
     "detect-libc": "^1.0.3"
   },
   "devDependencies": {

packages/optimizers/image/src/ImageOptimizer.js

@@ -5,13 +5,15 @@ import {Optimizer} from '@parcel/plugin';
 import {blobToBuffer} from '@parcel/utils';
 import {md} from '@parcel/diagnostic';
 import {optimize} from '../native';
+import WorkerFarm from '@parcel/workers';
 
 export default (new Optimizer({
   async optimize({bundle, contents, logger}) {
     if (!bundle.env.shouldOptimize) {
       return {contents};
     }
 
+    await loadOnMainThreadIfNeeded();
     let buffer = await blobToBuffer(contents);
 
     // Attempt to optimize it, if the optimize fails we log a warning...
@@ -34,3 +36,27 @@ export default (new Optimizer({
     return {contents: buffer};
   },
 }): Optimizer);
+
+// On linux with older versions of glibc (e.g. CentOS 7), we encounter a segmentation fault
+// when worker threads exit due to thread local variables in Rust. A workaround is to
+// also load the native module on the main thread, so that it is not unloaded until process exit.
+// See https://github.com/rust-lang/rust/issues/91979.
+let isLoadedOnMainThread = false;
+async function loadOnMainThreadIfNeeded() {
+  if (
+    !isLoadedOnMainThread &&
+    process.platform === 'linux' &&
+    WorkerFarm.isWorker()
+  ) {
+    let {family, version} = require('detect-libc');
+    if (family === 'glibc' && parseFloat(version) <= 2.17) {
+      let api = WorkerFarm.getWorkerApi();
+      await api.callMaster({
+        location: __dirname + '/loadNative.js',
+        args: [],
+      });
+
+      isLoadedOnMainThread = true;
+    }
+  }
+}

packages/optimizers/image/src/loadNative.js

@@ -0,0 +1,6 @@
+// This function is called from the main thread to prevent unloading the module
+// until the main thread exits. This avoids a segfault in older glibc versions.
+// See https://github.com/rust-lang/rust/issues/91979
+module.exports = () => {
+  require('../native');
+};