Two pass Fortran compilation may not be giving full advantage

Because Fortran source is compiled in batches, everything which can be compiled now, then re-evaluate, rather than a rolling process we may not be getting full value out of the two-pass approach.

No files or tests are named. Start by tracing the two-pass Fortran compilation entry point and how batches are re-evaluated; determine whether newly compilable sources are revisited before the process ends. Done means the two-pass approach fully realizes its intended benefit, with coverage or build evidence for the revised behavior.

Written by the indexing model from the issue text.