[Bug-tar] Inquiry - incremental archives using the --directory option not supported ?

[Jérome Foucher]

Hello there,

I'm running into an odd behavior. Hard to summarize it to a single sentence, so 
I'll write the full story below.

Here's what I do :
I create on a machine A a level 0 archive. Here's my command line:
        tar --create --listed-incremental=snapshot_0 --file=archive_0 
--directory=/Users/me/  Mail Documents

Mail and Documents are two directories inside /Users/me/

If I then add a file in the Mail folder and create a level 1 archive in the 
same machine A, it works nicely. The archive only contains the file I've added.
The command line is:
        tar --create --listed-incremental=snapshot_1 --file=archive_1 
--directory=/Users/me/  Mail Documents

Where of course, snapshot_1 was a duplicate of snapshot_0 before running the 
command line.

I use the --directory option so that the archive can be extracted on several 
other machines. And it can be extracted into another other place than the 
original /Users/me directory.
I have a master machine where I create the archives. And the archives are 
deployed onto a bunch if other machines. John will extract it into his 
/Users/john directory, Jack into his /Users/jack directory, and so on.


But let's say machine A is now dead. I move on to machine B, and extract the 
level 0 archive

I then add a file in the Mail folder and try to create a level 1 archive using 
the same command line as above.
Oddly, the archive_1 file is huge, and contains all the files in Mail and 
Documents directories. The incremental thing failed.

If I run this command line instead:
        tar --create --listed-incremental=snapshot_1 --file=archive_1 
/Users/me/Mail /Users/me/Documents

Then the archive_1 file only contains the file I've added in Mail....
But it's useless to me. I don't want to use absolute pathes. I really need to 
have relative pathes.
I cannot extract this level 1 archive into /Users/john as I did with the level 
0 archive.

Is this a bug of tar, or just me using it in a way it wasn't designed for ?

Note that I recently compiled the latest version of gnutar that includes the 
"--no-check-device" option. At first I thought this would solve my problem. 
Unfortunately, it didn't....

Any help greatly appreciated !!

Cheers,
Jérome