With the introduction of MacOS15 Sequoia, the mavens at Apple dropped support for MacOS12 Monterey. I held on for a month or so while two updates of the Microsoft Apps came and went without my laptop able to download them. Yesterday I tried to edit a Word file sent to me by someone. The older software was not working well in edit mode, so I decided to upgrade everything. I do not want to scale the heights of MacOS15 Sequoia yet, because it may introduce a new wrinkle in my legacy Fortran codes. Consulting the Apple help pages with the Google, I determined that one can upgrade to an older system through the App Store, so I followed the link to the latest version of MacOS13 Ventura, an operating system that Apple will probably support until Fall 2025. By then I will have upgraded my laptop to an Apple M4 chip and be digesting Sequoia on it. Both iMacs are currently running MacOS14 Sonoma without serious problems, but I havent been developing Fortran codes on them. So Ventura was the upgrade.
The upgrade notes from May 2023 worked successfully, installing MacPorts and then using MacPorts to install gcc12 and its gfortran code. The only wrinkle was the need to alter one of the MacPorts auxiliary files (sources.conf) to correct a misleading weblink for software tarballs. This file proved challenging to find on my laptop -- I needed the Google to find the breadcrumbs left by previous programmers with the same installation bug.
My altered legacy codes from 2023, changed to accommodate the syntax rules of Fortran 2018, worked OK. When compiled, there were many warnings about arrays out of bounds, owing to the past use of the old DIMENSION B(N,1) syntax that left the number of rows in an array open. A warning, not an error, so the codes can be used without changing all the DIMENSION statements.
In other housekeeping, I upgraded the ObsPy39 environment in Anaconda to ObsPy 1.4.1. Not tested yet. Need to sync with the iMacs, probably. Anaconda itself did not nudge me to upgrade the Navigator.