FreeBASIC can rebuild itself, but the path depends on what compiler and bootstrap sources are already available. The current make system keeps bootstrap logic in mk/bootstrap/ and exposes named targets for the common states.
make prereqs-fbc
make bootstrap-minimal
make bootstrap-seed-peer
make bootstrap-emit
make bootstrap-dist-targetThe right target depends on whether the host already has a usable fbc, a system package compiler, or target-specific generated bootstrap sources.
Start with make print-config and make prereqs-fbc. Bootstrap failures are usually easier to understand after confirming the selected host, target, bootstrap compiler, backend, binary names, and output directories.
If a new platform cannot even run a previous FreeBASIC compiler, generate or stage bootstrap sources from a platform that can. Avoid changing parser or code generation behavior just to make a bootstrap step pass until the failure has been traced to the real portability problem.