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Re: trixie: cdrecord can no longer write to CD



On 17/11/2025 15:55, Thomas Schmitt wrote:
Max Nikulin wrote:
Not being familiar with strace internals, I suspect that you may need to
patch the tool to add a special case for openat. Other alternatives are
debugger

I'm not that optimistic. :)

I had an idea to have a look into strace sources. First step was to locate its upstream repository, so "apt show strace". At
<https://strace.io/> I have noticed
*Print paths and more info associated with file descriptors.*

$ strace -yy cat /dev/null
...
openat(AT_FDCWD, "/dev/null", O_RDONLY) = 3</dev/null<char 1:3>>
fstat(3</dev/null<char 1:3>>, {st_mode=S_IFCHR|0666, st_rdev=makedev(0x1, 0x3),
...}) = 0
fadvise64(3</dev/null<char 1:3>>, 0, 0, POSIX_FADV_SEQUENTIAL) = 0
read(3</dev/null<char 1:3>>, "", 131072) = 0

Options "-y" "--decode-fds=path"and "-yy" "--decode-fds=all" in the man page look promising. I decided to stop at this point today.

On 17/11/2025 15:55, Thomas Schmitt wrote:
or auditd.

I'm not that smart.

Once I did it and it was not really difficult. I could not recall if I found suitable recipes or docs were enough. It is much easier than e.g. modifying and debugging SELinux rules.

 From my point of view, the main question is whether developers/maintainers
of wodim are active.

Not in wodim. I hope everybody is still well and active otherwise.

Then why the issue has not fixed yet. I would expect discussion with traces in the bug tracker and of course developers or maintainers should participate. (Unless only a part of users are affected it is not clear why. so more feedback is necessary.)

I am not sure if it is time to re-evaluate issues with license of original cdrecord.

Is it feasible to patch k3b and similar front-ends to use xorriso as an alternative backend?

 From links posted to the previous thread on this tool, my impression is that
wodim may fail trying to lock large enough chunk of RAM (that requires
specific capabilities).

I had hoped to see something like that in the strace output.

I would expect it namely for "wodim --devices". Reading the previous thread, I suspected that k3b adds some option to increase buffer size missed in your commands. Comments in RedHat bugzilla have contain commands.

In the 20 years that i work with libburn i never bonked against access
restricted SCSI commands.

Cdrecord created earlier, so wodim as its fork may still rely of vendor-specific commands.

There is no desktop active. So i have to set the usual ACL manually:

  $ sudo setfacl -m user:thomas:rw /dev/sr0

To avoid ambiguity, "uaccess" is a feature of systemd-logind based on an udev hint. Desktop environment is not required, it is enough to switch to proper user current "seat" (Ctrl+Alt+F<n>). Remote login may require manual setfacl.


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