return process.dlopen(module, path._makeLong(filename));

Try refreshing your installed modules by

$ rm -rf node_modules/
$ npm update

I got errors relating to process.dlopen when using Gulp and node-sass. Clearing the installed modules fixed the issue for me.

EDIT: Not certain how OpenCV works (or what it actually is), but I presume it handles NodeJS modules similarly to regular NodeJS applications, where you can refresh the module collection.

Use this command, it works fine:

npm rebuild bcrypt --build-from-source

You should check your OpenCV installation, it's probably either missing/can't be found or its not a version supported by the OpenCV node binding. Assuming you're using the opencv module on npm, its readme says that OpenCV versions from v2.3.1 until v3.0.0 are (fully) supported.