To compile in Cygwin console, additional installation is often required.
For example, gfortran is required to compile (build) Packmol.
However, default cygwin installation process does not include compilers (e.g., gcc, gfortran).
When installing Cygwin, we need to select necessary packages.
In a package search window, type "gcc" and then gcc packages will appear.
Change the default option into "install" or we can select particular packages in a subfolder.
In this way, other packages can be installed.
For example, to prepare MD simulation environment on Windows OS system, we will need:
required package of cygwin + python (for Moltemplate) + gcc (for Packmol) + make (for Packmol)
(gcc package includes gfortran)