This was on a 6-Core Intel Core i7 3.2 Ghz 2018 Intel Mac mini with 32GB of memory running Sequoia 15.0 and Xcode 16.0.  Homebrew is not installed.  gfortran 14.2.0 from gnu.org <http://gnu.org/> was compiled and installed on this system prior to running make check in libtool-2.4.7