rsync replacing symlinks without warning (resend)

[Kevin Korb]

I'm not really blaming the user.  If it were up to me, -v would include -i.

On 2/9/24 05:36, Andreas Gruenbacher wrote:
> On Sun, Feb 4, 2024 at 7:20 PM Kevin Korb via rsync
> <rsync at lists.samba.org> wrote:
>> rsync's -v is fairly useless.  Learn to use -i instead or in addition to.
> 
> Well, note that I didn't say anything about the lib/ directory in that
> command; it's just that rsync decided to remove the symlink component
> from the path lib/modules/.
> 
> Wouldn't it be more useful to make it obvious in the --verbose and
> --dry-run output what rsync has actually decided to do instead of
> blaming the user, which is what you're doing? Especially if the
> behavior is all but self-explanatory?
> 
> Thanks,
> Andreas
> 
>> On 2/4/24 12:58, Andreas Gruenbacher via rsync wrote:
>>> Hello,
>>>
>>> when trying to rsync files between hosts, I ran into a surprising case
>>> in which rsync replaces a symlink with a directory, with no indication
>>> of any kind.
>>>
>>> In the following reproducer, rsync is called as follows:
>>>
>>>     rsync --verbose --recursive --relative --delete a/./lib/modules b/
>>>
>>> Directory b contains a 'lib' symlink pointing to 'usr/lib', and rsync
>>> removes that and replaces it with a directory.
>>>
>>> In my real-world use case, this caused '/lib' -> '/usr/lib' symlinks
>>> to be replaced with '/lib' directories, which left the receiving test
>>> machines in a fairly sad state.
>>>
>>> I have since figured out that I can get rsync to behave as expected by
>>> adding the --keep-dirlinks option, but ...
>>>
>>> it's very unfortunate that when rsync does that kind of thing, it
>>> leaves no indication in the 'rsync --dry-run' and 'rsync -v' output.
>>> Could that please be fixed?
>>>
>>> Thanks,
>>> Andreas
>>>
>>>
>>> #! /bin/sh
>>>
>>> tmp=$(mktemp -dt ${0##*/}.XXXXXXXXXX)
>>> trap 'cd /; rm -rf $tmp' EXIT
>>> cd "$tmp"
>>>
>>> umask 022
>>>
>>> mkdir -p a/lib/modules
>>> echo foo > a/lib/modules/foo
>>>
>>> mkdir -p b/usr/lib/modules
>>> ln -s usr/lib b/lib
>>>
>>> show() {
>>>       find "$@" | xargs stat -c "%F %N" | sort -k2
>>> }
>>>
>>> echo "from:"
>>> show a
>>>
>>> echo
>>> echo "to:"
>>> show b
>>>
>>> echo
>>> echo "rsync:"
>>> rsync \
>>>       --verbose \
>>>       --recursive \
>>>       --relative \
>>>       --delete \
>>>       a/./lib/modules \
>>>       b/
>>>
>>> echo
>>> echo "to:"
>>> show b
>>>
>>> # SCRIPT OUTPUT with rsync 3.2.7:
>>> # ==============================
>>> =
>>> # from:
>>> # directory 'a'
>>> # directory 'a/lib'
>>> # directory 'a/lib/modules'
>>> # regular file 'a/lib/modules/foo'
>>> #
>>> # to:
>>> # directory 'b'
>>> # directory 'b/usr'
>>> # directory 'b/usr/lib'
>>> # directory 'b/usr/lib/modules'
>>> # symbolic link 'b/lib' -> 'usr/lib'
>>> #
>>> # rsync:
>>> # sending incremental file list
>>> # lib/
>>> # lib/modules/
>>> # lib/modules/foo
>>> #
>>> # sent 160 bytes  received 47 bytes  414.00 bytes/sec
>>> # total size is 4  speedup is 0.02
>>> #
>>> # to:
>>> # directory 'b'
>>> # directory 'b/lib'
>>> # directory 'b/lib/modules'
>>> # directory 'b/usr'
>>> # directory 'b/usr/lib'
>>> # directory 'b/usr/lib/modules'
>>> # regular file 'b/lib/modules/foo'
>>>
>>>
>>
>> --
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