Re: Question about automake fails to pass the correct parameters to pax when using large UID/GID

[xufeng zhang]

On 10/30/2010 03:37 PM, Ralf Wildenhues wrote:
> Hello Xufeng Zhang,
>
> thanks for the report.
>
> * xufeng zhang wrote on Wed, Oct 27, 2010 at 05:24:18AM CEST:
>    
> > I'm a developer from WindRiver, and I have a question about automake.
> > When I using a large UID/GID(>2097151) to configure and build a
> > linux project,
> > gnu tar fails and automake select pax as a replacement. However,
> > automake seems
> > fail to pass the correct parameters to pax(we are using ustar as
> > archive format),
> > the build hangs at:
> >      
> [...]
>
>    
> > checking how to create a ustar tar archive...
> > ATTENTION! pax archive volume change required.
> > Ready for archive volume: 1
> > Input archive name or "." to quit pax.
> > Archive name>
> >
> > I think the problem is caused by the maximum limitation of UID/GID
> > for ustar archive format
> > (Maximum value of UID/GID is 2097151). So if it is proper to
> > increase the limitation for UID/GID in ustar?
> > I don't know if there is any considerations for this limitation?
> >      
> I don't think there is much that can be done about this in Automake, as
> that seems to be a limitation inheren in the ustar format.  See
>    info Automake --index 'ustar format'
>
> and the link to the Formats node of the GNU tar manual a couple of
> paragraphs further down.
>
> IIUC then you'd either have to change to a different UID/GID with lower
> values, or modify the package to use a different archive format.
>
> If you still think that Automake is in the position to do something
> about this, then please provide more details (as I'm not exactly an
> expert in archive formats portability).
>    
It seems pax has a potential bug which leads to the whole build hang.
When use a large GID(>2097151), pax failed to generate file, then if
use the generated file as pax input, pax cannot recognize the format and
wait input from the terminal.
Try this:
1. mkdir conftest.dir
2. sudo chgrp -R 12345678 conftest.dir
3. sudo pax -L -x ustar -w conftest.dir > conftest.tar
4. pax -r < conftest.tar
Then pax will definitely hang.

Thanks,
Xufeng Zhang
> Thanks,
> Ralf
>