I'm working on a complex translation layer package, which is here. I'm using the C names as swift source file names to make maintaining easier.
I started getting this error
error: command Compiling Swift Module 'Direct3D12' (305 sources) failed: unable to spawn process 'C:\Library\Developer\Toolchains\unknown-Asserts-development.xctoolchain\usr\bin\swiftc.exe' (The filename or extension is too long.)
The error is not for a single swift source file, rather it happens because the total length of all paths in the swift target are too long. The error goes away if a remove enough source files, and it doesn't matter which files.
Is this a known compiler limitation or a bug?
This is happening on Windows. The package would need a decent amount of work to be built on other platforms to test if this is a platform issue.