Bug#731806: debian-installer: FTBFS on sparc: genisoimage errors

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

> I may provide you access to a shell account on my machines if needed.

Yes, please.

Plus a directory tree
  ./tmp/miniiso/cd_tree
which can cause the xorriso crash.


> Sparc architecture is extremely picky about alignement. Bad alignement,
> yields SIGSEGV whereas intel only do it in the less efficient way.

I would suspect the habit of my libisofs predecessor developer
to use structs as access frame for byte arrays read from file.

But why then was it possible to produce
  debian-7.4.0-sparc-netinst.iso
by xorriso-1.2.6 as can be read from its "Preparer Id":
  XORRISO-1.2.6 2013.01.08.103001, LIBISOBURN-1.2.6, LIBISOFS-1.2.6, LIBBURN-1.2.6
Does debian-cd pull "sparc" trees onto a non-sparc machine ?


> [genisoimage]
> (gdb) x rpnt
> 0x1ea7f9:    0x00000000
> (gdb) x lpnt
> 0x1e9dc1:    0x01000000
> (gdb) n
> 659        if (strcmp(rpnt, lpnt) == 0) {

Both values match the prescribed names for "." and ".." in ECMA-119
(aka ISO 9660), 6.8.2.2 Identification of directories:
Single byte 0x00 is ".", single byte 0x01 is "..".

> So, strcmp shouldn't have yielded 0 when comparing the strings.

Can this be caused by alignment problems ?


> Hum, unfortunately, valgrind is not available for sparc.

Then gdb will have to do.


> xorriso is the one compiled from isoburn. I tried with the one from the
> archive, and the one rebuild from source with a debbuild.
> Same problem on both.

If you also built libisofs and libburn from source, then this burries
my theory of a binary incompatibility between two SPARC machines.

> I'm compiling at this moment the vanilla xorriso from gnu.
> Let's see what it yields.

It has the same source as the three library tarballs used as input
for Debian's xorriso. Only difference is that GNU xorriso brings
own copies of the library source code and links it statically with
the xorriso main program.
So it can be easily tested without interfering with installations
of the libraries. (And with no need for superuser privileges.)


Have a nice day :)

Thomas