It may be because I'm not developing a traditional Swift app, instead I'm using the https://github.com/zserge/webview library to develop a cross platform app.
My app has 2 parts, divided into 2 different threads: one thread launches the window and displays a JS app. The second thread contains a background server bound to an ephemeral port and serves a json api, written in Rust. The Rust side is also the one talking with the File System and making all requests. On Linux I don't have any problem, but on Mac it works only when requesting resources from root and home directories but not from Documents/Desktop etc
The first problem I had when running it on Mac has been allowing access to the server from the window: I had to add a new entry to the info.plist file, according to this answer in stackoverflow: The resource could not be loaded because the App Transport Security policy requires the use of a secure connection
This resolved the issue I had talking to the server bound to the ephemeral port. Truth be said I have to also say that now it requests me to allow access to external resources every time I launch the app.
But, when trying to execute a function which requires access from the Rust side to the Desktop (for example), it doesn't work and it does not show any popup and never did
Btw, if you want to have a look at the final product, maybe to help you understand better the app, have a look here: http://getdevspace.com/