React native 0.68.2 iOS with Hermes enabled not able to load the application, metro error

[chirag-blueed]

Can you suggest a solution, or is this issue specific to iOS when Hermes is enabled?
Note: This happens only with hermes enabled in my project, with default JavaScript Core it is working fine
Can some one suggest a fix of it

ERROR ReferenceError: Property 'module' doesn't exist, js engine: hermes Error: ENOENT: no such file or directory, open '/Users//Workspace//webpack:/multi_./src/index.js?' at Object.openSync (node:fs:596:3) at Object.readFileSync (node:fs:464:35) at getCodeFrame (/Users//Workspace//node_modules/metro/src/Server.js:949:18) at Server._symbolicate (/Users//Workspace//node_modules/metro/src/Server.js:1022:22) at process.processTicksAndRejections (node:internal/process/task_queues:95:5) at async Server.processRequest (/Users//Workspace//node_modules/metro/src/Server.js:429:7) { errno: -2, syscall: 'open', code: 'ENOENT', path: '/Users//Workspace//webpack:/multi./src/index.js?'

Error: ENOENT: no such file or directory, open '/Users/*/Workspace/*/*/webpack:/multi_./src/index.js?' at Object.openSync (node:fs:596:3) at Object.readFileSync (node:fs:464:35) at getCodeFrame (/Users/*/Workspace/*/*/node_modules/metro/src/Server.js:949:18) at Server._symbolicate (/Users/*/Workspace/*/*/node_modules/metro/src/Server.js:1022:22) at process.processTicksAndRejections (node:internal/process/task_queues:95:5) at async Server._processRequest (/Users/*/Workspace/*/*/node_modules/metro/src/Server.js:429:7) { errno: -2, syscall: 'open', code: 'ENOENT', path: '/Users/upforcetech/Workspace/*/*/webpack:/multi_./src/index.js?' }

[tmikov]

From your screenshot, your code is relying on "local eval", that is compilation of JavaScript source at runtime in the context of a function, accessing symbols declared in that function.

(function(module) {
   eval("module.exports = ...."); 
   ...
})

Local eval is not supported by Hermes (in general Hermes is optimized for running from bytecode - compilation from source on device is very slow).

[chirag-blueed]

But @tmikov how can I fix this? Could you please help me?

[chirag-blueed]

The release build works fine, but the debug build has issues when connected to the Metro server bundler.
@tmikov Can you re-open the bug?

[tmikov]

Sorry, @chirag-blueed, I wish I could help you, but I don't have a good practical understanding of how JS apps are packaged and built in practice. The Hermes team deals primarily with C++ and narrow JS language features. You might have better luck asking in React Native.

Take the following with a grain of salt: From what I can tell, there is Webpack usage in your code, and for some reason it is wrapped in an eval(). No idea why, but that's where I would start. AFAIK, RN apps are usually packaged with Metro, not Webpack.