Rebuilding the model

You should rebuild the model under the following circumstances:

If either env_build.xml or Macros has been modified, and/or if code is added to SourceMods/src.*, then it's safest to clean the build and rebuild from scratch as follows,

> cd $CASEROOT
> ./case.build --clean 

If you have ONLY modified the PE layout in env_mach_pes.xml (see setting the PE layout <http://www.cesm.ucar.edu/models/cesm2.0/external-link-here>_) then it's possible that a clean is not required.

> cd $CASEROOT
> ./case.build

But if the threading has been turned on or off in any component relative to the previous build, then the build script should fail with the following error

  ERROR SMP STATUS HAS CHANGED
    SMP_BUILD = a0l0i0o0g0c0
    SMP_VALUE = a1l0i0o0g0c0
    A manual clean of your obj directories is strongly recommended
    You should execute the following:
      ./case.build --clean
      ./case.build
    
    ---- OR ----
    You can override this error message at your own risk by executing
      ./xmlchange SMP_BUILD=0 
    Then rerun the build script interactively

and suggest that the model be rebuilt from scratch.

You are responsible for manually rebuilding the model when needed. If there is any doubt, you should rebuild.