mapl-error-handling

MAPL error handling macros in Fortran work by wrapping return code checks, such as using `_RC` to capture errors and `_VERIFY` to assert success. They enforce return code standards and provide informative error messages for GEOS-ESM modules.

The best way to debug return code failures in MAPL is to use the `_FAIL` and `_HERE` macros. `_FAIL` outputs informative error messages when an error condition is met, while `_HERE` pinpoints the exact source file and line number during execution.

To validate allocations and file operations in Fortran using MAPL, apply the `_IOSTAT` and `_STAT` macros to capture operation statuses. Follow this with `_VERIFY` or `_ASSERT` to immediately catch and handle any runtime failures according to MAPL conventions.

Common pitfalls with MAPL error handling conventions include skipping return code checks on allocations and file I/O, or using uninformative error messages. Avoid these by consistently applying `_RC` and `_VERIFY` to ensure all potential errors are caught and reported.