Re: Fwd: Bug#1050663: dar option --on-fly-isolate creates catalogue with broken slice_layout

On 29/08/2023 04:50, John Goerzen wrote:
> On Mon, Aug 28 2023, Denis Corbin wrote:
> 
>>
>> I could not reproduce it with neither 2.7.9 nor 2.7.10 on my system. Will try
>> under Debian to see what's wrong, keep you informed.
> 
> Interestingly, I could duplicate this with the dar version in
> bookworm-backports, but not with the one in sid.  Both are 2.7.10.
> That's odd!

Thanks for that, I have installed a pristine Debian 12 adding the 
backports repo and I could reproduce it:
- first using the Debian provided binary
- then using the deb-src package and compiling the provided source code
   (which include tiny and harmless patch to adapt to Debian rules)
- then using the upstream source code alone

The problem disappears just removing the default compilation -O2 options:

export LDFLAGS=-g
export CFLAGS=-g
export CXXFLAGS=-g
./configure
make

The problem also disappear when replacing gcc-12 by the clang 14 compiler.

I can't troubleshoot any further, as I need to remove the default 
optimization options, to step in the execution (else it is really 
difficult to link binary to source code, gdb is lost most of the time)

As far as I can understand, problem seems coming from gcc-12 and not the 
linking process (ld) nor external library nor Debian added patches nor 
the upstream source code.

> 
> On the Debian side:
> 
> - In dar 2.7.9-1, I enabled librsync support, and required libcap-dev and
>    libnsl-dev.
> 
> - In dar 2.7.9-2, I enabled libthreadar, curl, and OpenSSL support.
> 
> - In 2.7.10-1, I enabled building the Python bindings.
> 
> I don't immediately see how any of these could be relevant here, but
> thought I'd mention in case it's a clue.

I would check the output of "dar -V", which reports the compiler used: I 
hope this will  confirm the link with gcc-12.

> 
>>
>> Regards,
>> Denis
>>
>> [[End of PGP Signed Part]]
>