Is this supposed to build?

[jrmuizel]

It doesn't seem to have the scratch files necessary for bootstrapping.

[mingodad]

At first yes, but in practice it's trick.
I did a refactoring/cleanup here https://github.com/mingodad/cfront-3 and have it building for Linux 32/64, Cross compiled to Windows 32/64 and OSX 64 bits, see here the github workflow and the output for it https://github.com/mingodad/cfront-3/actions/runs/1421141006/workflow