https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88653
--- Comment #18 from Murat Tekeev <mtekeev at yandex dot ru> --- Unfortunately, I was happy too soon. I made a mistake - with Fortran 7.4 these files still do not compile. Apparently I installed the latest version of Cygwin on three different machines, the installation is fine, but not all files are compiled. I don't know what the problem is. With gfortran 7.3 no problems. I will continue to use gfortran 7.3 and wait until the next version of Cygwin is released. Apparently, this is some kind of cygwin problem.
