Re: Native symbolic link behavior is broken and makes backups using Cygwin command line tools impossible

["Matt D." <codespunk@gmail.com>]

Did you try any of my test cases? This can't and doesn't work for the
reasons I outlined in my previous message:

$ cp -av folder_a/a folder_b/
'folder_a/a' -> 'folder_b/a'
cp: cannot create symbolic link 'folder_b/a': No such file or directory

$ cp -dv folder_a/a folder_b/
'folder_a/a' -> 'folder_b/a'
cp: cannot create symbolic link 'folder_b/a': No such file or directory

$ cp -Pv folder_a/a folder_b/
'folder_a/a' -> 'folder_b/a'
cp: cannot create symbolic link 'folder_b/a': No such file or directory

On Sun, Jan 3, 2021 at 12:00 AM Brian Inglis
<Brian.Inglis@systematicsw.ab.ca> wrote:
>
> On 2021-01-02 21:16, Matt D. via Cygwin wrote:
> > I have a folder with a lot of native Windows symbolic links. I want to
> > copy this folder.
> >
> > I cannot rsync or cp this folder due to Cygwin being unable to create
> > symbolic links without also wanting to verify the link target. This
> > can be demonstrated:
> >
> > $ ln -s a b
> > ln: failed to create symbolic link 'b': No such file or directory
> >
> > If I create a test directory folder_a/ and folder_b/. Inside I will
> > "touch a" and "ln -s a b".
> >
> > I cannot rsync this folder:
> >
> > $ rsync -a folder_a/ folder_b/
> > rsync: symlink "folder_a/b" -> "a" failed: No such file or directory (2)
> > rsync error: some files/attrs were not transferred (see previous
> > errors) (code 23) at main.c(1306) [sender=3.2.0dev]
> >
> > Using "cp -a folder_a/* folder_b/" in this test case DOES work but
> > this is simply because files were returned in the correct order and
> > the link could be created.
> >
> > This can be demonstrated where this works fine:
> >
> > $ cp -a folder_a/a folder_a/b folder_b/
> >
> > But this does not:
> >
> > $ cp -a folder_a/b folder_a/b folder_b/
> > cp: cannot create symbolic link 'folder_b/b': No such file or directory
> > cp: warning: source file 'folder_a/b' specified more than once
> >
> > The order in which files are returned while listing them in a
> > directory and necessitating their pre-existence while performing a
> > deep copy is impossible. It's also very normal for symbolic links to
> > exist which may or may not point to a valid target depending on the
> > observing path.
> >
> > Windows does NOT require a link to be valid before creation. This can
> > be demonstrated with mklink:
> >
> > C:\mklink b a
> > symbolic link created for b <<===>> a
>
> Depending on exactly what you have and what you want to do try:
>
>         $ cp -av
>         $ cp -dv
>         $ cp -Pv
> or
>         > robocopy /sl
>
> --
> Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
>
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