`model_names` contains names of non-existing models

[pya]

Model

The following was produce with the model ex-gwt-gwtgwt-p10 form the recent MODFLOW 6 examples: built 02/06/2025 19:17.

Code

This code:

from modflowapi import Callbacks, run_simulation

def callback(sim, callback_step):
    if callback_step == Callbacks.initialize:
        print(sim.model_names)

run_simulation(
    dll='path/to/libmf6.dylib',
    sim_path='path/to/ex-gwt-gwtgwt-p10',
    callback=callback,
)

produces this output:

['gwf-outer', 'gwt-outer', 'gwt-inner', 'gwtim2_2', 'gwf-inner', 'gwtim1_2']
NORMAL TERMINATION OF SIMULATION

Versions

• modflowapi: 0.3.0.dev0
• xmipy: 1.3.1
• MODFLOW: 6.6.1

Expected behavior

The file mfsim.nam in the directory ex-gwt-gwtgwt-p10 looks like this:

# File generated by Flopy version 3.10.0.dev1 on 02/06/2025 at 18:50:25.
BEGIN options
END options

BEGIN timing
  TDIS6  ex-gwt-gwtgwt-p10.tdis
END timing

BEGIN models
  gwf6  gwf-outer.nam  gwf-outer
  gwf6  gwf-inner.nam  gwf-inner
  gwt6  gwt-outer.nam  gwt-outer
  gwt6  gwt-inner.nam  gwt-inner
END models

BEGIN exchanges
  GWF6-GWF6  ex-gwt-gwtgwt-p10.gwfgwf  gwf-outer  gwf-inner
  GWT6-GWT6  ex-gwt-gwtgwt-p10.gwtgwt  gwt-outer  gwt-inner
  GWF6-GWT6  outer.gwfgwt  gwf-outer  gwt-outer
  GWF6-GWT6  inner.gwfgwt  gwf-inner  gwt-inner
END exchanges

BEGIN solutiongroup  1
  ims6  gwfsolver.ims  gwf-outer  gwf-inner
  ims6  gwtsolver.ims  gwt-outer  gwt-inner
END solutiongroup  1

There are only four model names:

• gwf-outer
• gwt-outer
• gwt-inner
• gwf-inner

These model names are not defined in mfsim.nam :

• gwtim2_2
• gwtim1_2

Where do they come from and what do they mean?

Other models with the same behavior

The example models ex-gwt-gwtgwt-p10 and ex-gwf-u1gwfgwf-s3 have additional model names too.

[jlarsen-usgs]

@pya
I'll have to look into this, but my guess is that the current version of the code is picking up on an internal exchanges or interface models and setting them as models. I'm currently doing some work in the api extensions and will add this to the list of things to investigate.