Wrong file names in MODFLOW examples input files for head and budget

[pya]

Problem

Running the examples (02/06/2025) ex-prt-mp7-p04 and ex-prt-mp7-p04 gives this error:

                                   MODFLOW 6
                U.S. GEOLOGICAL SURVEY MODULAR HYDROLOGIC MODEL
                            VERSION 6.6.1 02/10/2025

        MODFLOW 6 compiled Feb 10 2025 17:05:58 with GCC version 13.3.0

This software has been approved for release by the U.S. Geological 
Survey (USGS). Although the software has been subjected to rigorous 
review, the USGS reserves the right to update the software as needed 
pursuant to further analysis and review. No warranty, expressed or 
implied, is made by the USGS or the U.S. Government as to the 
functionality of the software and related material nor shall the 
fact of release constitute any such warranty. Furthermore, the 
software is released on condition that neither the USGS nor the U.S. 
Government shall be held liable for any damages resulting from its 
authorized or unauthorized use. Also refer to the USGS Water 
Resources Software User Rights Notice for complete use, copyright, 
and distribution information.


 MODFLOW runs in SEQUENTIAL mode

 Run start date and time (yyyy/mm/dd hh:mm:ss): 2025/03/18 21:31:46

 Writing simulation list file: mfsim.lst
 Using Simulation name file: mfsim.nam


ERROR REPORT:

  1. Could not find file ../gwf/mp7-p02-gwf_bkwd.hds

UNIT ERROR REPORT:

  1. Error occurred while reading file 'mp7-p02-prt.fmi'

Solution

Rename the *.hds and *.cbb files in mp7-p02-prt.fmi, removing the postfix _bkwd. Furthermore, the extenion *.bud in ex-prt-mp7-p04/mp7-p04-prt.fmi needs to be changed to cbb.

[wpbonelli]

@pya these two examples cannot run out of the box yet. Pending native backwards tracking, we use flopy to reverse the head and budget files. Really it would be cleaner not to distribute these until natively supported, but in the meantime, you can run the python script instead of the model files, or use e.g. python -m flopy.utils.binaryfile.reverse ... before the tracking model as is now supported. We are still ironing some bugs out of all this. It is still a bit sketchy, but it should work for these examples at least. Let us know if you run into issues.

[pya]

@wpbonelli Thanks for your explanation. It is not essential now. I ran all examples with modflowapi. So I stumble over it. I will just ignore these two examples for now and try again with the next release.

BTW, the instructions say:

Any issues with the MODFLOW 6 examples should be posted on the main MODFLOW 6 GitHub repo and flagged with the examples label.

I couldn't figure out how to set a label.