Comment 13 for bug 556653

Attaching the transcript of the debug session.

Upon entering the chroot env, after receiving the error once, I cleaned the remnant initrd file.
The I modified the postinst script inserting a set -x, set GL to be provided by MESA and reconfigured the package. No errors.
Then I configured nvidia for GL and reconfigured again the package. Errors are shown in the log.
Finally I edited the postinst again, insterted the above check and reconfigured the package. No errors.