bug#20438: coreutils 8.23 on OS X : Calling gcp -al fails on symbolic links

[Pádraig Brady]

On 27/04/15 12:34, Thomas Baigneres wrote:
> Hello,
>
> Consider the following directory hierarchy:
>
>       $ ls -lR
>       total 0
>       drwxr-xr-x  4 user  group  136 Apr 24 13:51 source
>
>       ./source:
>       total 16
>       -rw-r--r--  1 user  group  0 Apr 24 13:50 file.txt
>       lrwxr-xr-x  1 user  group  8 Apr 24 13:51 symbolic-link-to-file -> 
> file.txt
>
>
> Trying to copy the `source` directory with the options -a (archive) and -l
> (hard link files instead of copying) fails when using the 8.23 version
> of coreutils:
>
>       $ gcp -al source destination
>       gcp: cannot create hard link 'destination/symbolic-link-to-file' to
>       'source/symbolic-link-to-file': Operation not supported
>
> Trying to do the same with the 8.22 version of coreutils works as
> expected :
>
>       $ gcp -al source destination
>       $ ls -lR
>       total 0
>       drwxr-xr-x  4 user  group  136 Apr 24 13:51 destination
>       drwxr-xr-x  4 user  group  136 Apr 24 13:51 source
>
>       ./destination:
>       total 16
>       -rw-r--r--  2 user  group  0 Apr 24 13:50 file.txt
>       lrwxr-xr-x  1 user  group  8 Apr 24 13:51 symbolic-link-to-file -> 
> file.txt
>
>       ./source:
>       total 16
>       -rw-r--r--  2 user  group  0 Apr 24 13:50 file.txt
>       lrwxr-xr-x  1 user  group  8 Apr 24 13:51 symbolic-link-to-file -> 
> file.txt
>
>
> Searching the internet suggests that the culprit might be the `linkat()`
> function, which exists but does not work as expected by coreutils.
>

Yes coreutils 8.23 uses linkat() for that where available:
http://git.sv.gnu.org/gitweb/?p=coreutils.git;a=commitdiff;h=v8.22-23-g9654b67

BTW this issue on OS X 10.10 is caught by gnulib and coreutils tests.
I.E. `make check` may be being ignored on your build?

There was initial work to fix this at:
http://git.sv.gnu.org/gitweb/?p=gnulib.git;a=commit;h=c8e57ce5

That doesn't fix everything though I think,
and I'll need to look into a complete fix for Mac OS X >= 10.10
(or revert to the previous coreutils behavior).

cheers,
Pádraig.