Disable dynamic import for unix-dgram causing memory leak

nodejs/node#42080
vercel/next.js#34659 (comment)

lib/transport.js

@@ -3,9 +3,7 @@ const dgram = require('dgram');
 const net = require('net');
 const dns = require('dns');
 const { PROTOCOL } = require('./constants');
-
-// Imported below, only if needed
-let unixDgram;
+const unixDgram = require('unix-dgram');
 
 const UDS_PATH_DEFAULT = '/var/run/datadog/dsd.socket';
 
@@ -87,16 +85,6 @@ const createUdpTransport = args => {
 };
 
 const createUdsTransport = args => {
-  try {
-    // This will not always be available, as noted in the error message below
-    unixDgram = require('unix-dgram'); // eslint-disable-line global-require
-  } catch (err) {
-    throw new Error(
-      'The library `unix_dgram`, needed for the uds protocol to work, is not installed. ' +
-        'You need to pick another protocol to use hot-shots. ' +
-        'See the hot-shots README for additional details.'
-    );
-  }
   const udsPath = args.path ? args.path : UDS_PATH_DEFAULT;
   const socket = unixDgram.createSocket('unix_dgram');
 

package.json

@@ -34,14 +34,14 @@
     "lint": "eslint lib/**/*.js test/**/*.js",
     "pretest": "npm run lint"
   },
-  "optionalDependencies": {
-    "unix-dgram": "2.0.x"
-  },
+  "optionalDependencies": {},
   "devDependencies": {
     "eslint": "5.9.x",
     "mocha": "6.2.x",
     "nyc": "15.x"
   },
   "license": "MIT",
-  "dependencies": {}
+  "dependencies": {
+    "unix-dgram": "2.0.x"
+  }
 }