It has been broken for a long time, may be longer than ROSA has been
using nrj kernels. The tool relied on the version and release numbers of
the kernel packages to find the proper ones - but these numbers have
been (1, 1) for at least several years now.
The relevant parts of urpm-package-cleanup have been rewritten.
There are a few more notable differences compared to the old
implementation:
1. The number of kernels to keep is now read from
/etc/urpmi/kernels.cfg.
2. --count option is no longer supported.
3. If remove_old_kernels is set to no in /etc/urpmi/kernels.cfg,
urpm-package-cleanup --oldkernels will have no effect. This may be
convenient when running urpm-package-cleanup from scripts, etc.
4. The packages required by any kernel*-latest package will not be
removed, so urpm-package-cleanup may keep more kernels than requested.