Re: Unclear error message when using -append-partition

[Thomas Schmitt]

Hi,

Brian C. Lane wrote:
> I didn't pass that absolute path in the line:
> -append-partition 2 C12A7328-F81F-11D2-BA4B-00A0C93EC93B images/efiboot.img
> and the error reported was:
> [...]
> libisofs: FAILURE : Cannot open data file for appended partition
> [...]
> It would be helpful if error messages like this would print the path of
> the file they were looking for and did not find.

Indeed.
It's a typical pitfall of happy programming that diagnostic messages are
only clear to the programmer and sometimes only while they are fresh in
the code.

In this special case it is also about the inner architecture of libisofs
(once laid out by its founder Vreixo Formoso Lopes), which works with
numeric error codes to produce text messages:

libisofs/messages.c
    ...
    case ISO_BAD_PARTITION_NO:
        return "Partition number out of range";
    case ISO_BAD_PARTITION_FILE:
        return "Cannot open data file for appended partition";
    case ISO_NON_MBR_SYS_AREA:
        return "May not combine MBR partition with non-MBR system area";
    ...

When i look in the code for ISO_BAD_PARTITION_FILE i come to several
occasions which all could need mentioning of the file path.
I will have to think about a more general reporting of bad file paths.

Thanks for this feedback.


I now got your mail from devel@lists.fedoraproject.org which reports
about the successful change from ISOLINUX to GRUB.
Congrats.

Please give me a note when such an ISO is ready for downloading.
I would like to add it to my collection of ISOs for regression tests.
(Before releases i run a loop which mounts and repacks existing ISOs
and then compares the resulting boot lures with those of the original
ISO.)

The test on "qemu bios -cdrom" gives good hope for success with real
optical media. Other than OVMF the SeaBIOS firmware is not known to
deal with CD-ROM the same way as with HDD.


Have a nice day :)

Thomas