How to Build Telegram for macOS

Clone this repository with submodules:

git clone https://github.com/overtake/TelegramSwift.git --recurse-submodules

brew install cmake ninja openssl@1.1 zlib
Open Telegram-Mac.xcworkspace in Xcode 10.3. Avoid Xcode 10.11+ because it causes additional errors when building the libraries with optimizations turned on.
Select build target to Github and Run build.

If you want to develop a fork

Do first and second step above.
Change bundle Identifier and team-id. Easiest way is to search all mentions ru.keepcoder.Telegram and change it to your own. Team-id you can find on apple developer portal.
Obtain your API ID. Note: The built-in apiId is highly limited for api usage. Do not use it in any circumstances except verify binaries.
Open Telegram-Mac/Config.swift and repalce apiId and apiHash from previous step. Note: Do not forget to change teamId either.
Replace or remove SFEED_URL and APPCENTER_SECRET in *.xcconfig files. (First uses for in-app updates and second for collecting crashes on appcenter)
Write new better code.
If you still have a questions feel free to open new issue here.