@vsajip @FFY00: Are you ok with this change? It uses symlinks by default on Cygwin when using the Python API (venv module). The python -m venv command line interface already uses symlinks by default on Unix:

    if os.name == 'nt':
        use_symlinks = False
    else:
        use_symlinks = True
    group = parser.add_mutually_exclusive_group()
    group.add_argument('--symlinks', default=use_symlinks,
                       action='store_true', dest='symlinks',
                       help='Try to use symlinks rather than copies, '
                            'when symlinks are not the default for '
                            'the platform.')

venv created with --copies doesn't work on Cygwin:

vstinner@win ~/cpython
$ ./python.exe -m venv ../env --without-pip --copies

vstinner@win ~/cpython
$ cd ../

vstinner@win ~
$ env/bin/python.exe -V
C:/cygwin64/home/vstinner/env/bin/python.exe: error while loading shared libraries: cygpython3.16d.dll: cannot open shared object file: No such file or directory

venv created with symlinks just works well:

vstinner@win ~/cpython
$ ./python.exe -m venv ../env --without-pip

vstinner@win ~/cpython
$ cd ..

vstinner@win ~
$ env/bin/python.exe -V
Python 3.16.0a0

With this change, venv cannot be used in copy mode: running the venv python programs fails to locate the libpython DLL.

I wrote a different approach, copy the libpython DLL in the venv: PR gh-150483.