When trying to build Embedded Swift with ESP-IDF on Linux, you may encounter the following error:
CMake Error at /usr/share/cmake-3.30/Modules/CMakeDetermineSwiftCompiler.cmake:52 (message):
Swift language not supported by "Unix Makefiles" generator
The problem is caused by missing ninja tool, since ESP-IDF does not support make anymore.
Solution to the problem is simple, just install ninja.
Command for Ubuntu/Debian:
sudo apt install ninja-build
Now, just re-run the build.