Convention-Based Source Discovery

FoBiS can discover source directories automatically when your project follows common layout conventions — no src = entry required in the fobos file.

Detected layouts

When no explicit src setting is present, FoBiS checks the project root for these directories in order:

Directory	Convention
src/	Most common layout for libraries and tools
source/	Alternative used by some legacy projects
app/	Fortran-package-manager (fpm) style

The first directory that exists and contains at least one Fortran source file is used. If none of the candidates are found, FoBiS falls back to scanning the current directory (.), which is the pre-discovery behaviour.

A discovery message is printed so you can see what was selected:

[auto-discover] using source directory: src/

Explicit src always wins

Auto-discovery never overrides an explicit src setting. If your fobos file has src = ./my_sources, or you pass --src on the command line, discovery is skipped entirely.

Disabling discovery

fobis build --no-auto-discover

Or in the fobos file:

[default]
no_auto_discover = true

Example

Given:

myproject/
├── fobos
├── src/
│   ├── solver.F90
│   └── mesh.F90
└── tests/
    └── test_solver.F90

Running fobis build with no src = in the fobos file automatically scans src/ and compiles solver.F90 and mesh.F90.

Running fobis test (which also calls the builder) scans tests/ explicitly via the test runner and src/ for library sources.