###私はビルドするのにgfortranを必要とするプログラムをインストールしようとしています
最新のCygwin Fortranパッケージは gcc-fortran-7.3.0-3 。
gcc-fortran:GNUコンパイラコレクション(Fortran)
2018-06-26 17:34 0 usr/bin/f95 -> gfortran.exe
2018-06-26 17:43 934931 usr/bin/gfortran.exe
2018-06-26 17:43 0 usr/bin/x86_64-pc-cygwin-gfortran.exe -> usr/bin/gfortran.exe
2018-06-26 17:34 0 usr/lib/gcc/x86_64-pc-cygwin/7.3.0/finclude/
2018-06-26 17:31 9702 usr/lib/gcc/x86_64-pc-cygwin/7.3.0/finclude/ieee_arithmetic.mod
2018-06-26 17:31 2208 usr/lib/gcc/x86_64-pc-cygwin/7.3.0/finclude/ieee_exceptions.mod
2018-06-26 17:31 1251 usr/lib/gcc/x86_64-pc-cygwin/7.3.0/finclude/ieee_features.mod
2018-06-26 17:34 15411 usr/lib/gcc/x86_64-pc-cygwin/7.3.0/finclude/omp_lib.f90
2018-06-26 17:34 5335 usr/lib/gcc/x86_64-pc-cygwin/7.3.0/finclude/omp_lib.h
2018-06-26 17:34 2981 usr/lib/gcc/x86_64-pc-cygwin/7.3.0/finclude/omp_lib.mod
2018-06-26 17:34 610 usr/lib/gcc/x86_64-pc-cygwin/7.3.0/finclude/omp_lib_kinds.mod
2018-06-26 17:34 28053 usr/lib/gcc/x86_64-pc-cygwin/7.3.0/finclude/openacc.f90
2018-06-26 17:34 3466 usr/lib/gcc/x86_64-pc-cygwin/7.3.0/finclude/openacc.mod
2018-06-26 17:34 484 usr/lib/gcc/x86_64-pc-cygwin/7.3.0/finclude/openacc_kinds.mod
2018-06-26 17:34 12388 usr/lib/gcc/x86_64-pc-cygwin/7.3.0/finclude/openacc_lib.h
2018-06-26 18:58 20222483 usr/lib/gcc/x86_64-pc-cygwin/7.3.0/f951.exe
2018-06-26 17:31 210238 usr/lib/gcc/x86_64-pc-cygwin/7.3.0/libcaf_single.a
2018-06-26 17:31 13307770 usr/lib/gcc/x86_64-pc-cygwin/7.3.0/libgfortran.a
2018-06-26 17:31 1050584 usr/lib/gcc/x86_64-pc-cygwin/7.3.0/libgfortran.dll.a
2018-06-26 17:31 269 usr/lib/gcc/x86_64-pc-cygwin/7.3.0/libgfortran.spec
2018-06-26 17:28 187195 usr/share/info/gfortran.info.gz
2018-06-26 17:28 22196 usr/share/man/man1/gfortran.1.gz
ソース https://cygwin.com/cgi-bin2/package-cat.cgi?file=x86_64%2Fgcc-fortran%2Fgcc-fortran-7.3.0-3&grep=fortran
このパッケージは、 Cygwinインストールプログラム 。