`sbsign` does not issue any error if there is not enough disk space to create
the signed file using its `--output` option.

Example with enough disk space:

# ls -l /var/tmp/dracut.hDT7WY/uefi/linux.efi
-rwx------ 1 root root 88712928 Feb 13 12:01
/var/tmp/dracut.hDT7WY/uefi/linux.efi
# mktemp -d
/tmp/tmp.YC4iYlF8UF
# mount -t tmpfs -o defaults,size=100M tmpfs /tmp/tmp.YC4iYlF8UF
# sbsign --key /home/dev/sbsign/uefi-private.key --cert
/home/dev/sbsign/uefi-public.pem --output /tmp/tmp.YC4iYlF8UF/test.img
/var/tmp/dracut.hDT7WY/uefi/linux.efi
warning: data remaining[88700416 vs 88712928]: gaps between PE/COFF sections?
Signing Unsigned original image
# sbverify --cert /home/dev/sbsign/uefi-public.pem /tmp/tmp.YC4iYlF8UF/test.img
warning: data remaining[88702192 vs 88714704]: gaps between PE/COFF sections?
Signature verification OK


Example without enough disk space:

# ls -l /var/tmp/dracut.9SDv5P/uefi/linux.efi
-rwx------ 1 root root 88715488 Feb 13 10:23
/var/tmp/dracut.9SDv5P/uefi/linux.efi
# umount /tmp/tmp.YC4iYlF8UF
# mount -t tmpfs -o defaults,size=1M tmpfs /tmp/tmp.YC4iYlF8UF
# sbsign --key /home/dev/sbsign/uefi-private.key --cert
/home/dev/sbsign/uefi-public.pem --output /tmp/tmp.YC4iYlF8UF/test.img
/var/tmp/dracut.9SDv5P/uefi/linux.efi
warning: data remaining[88702464 vs 88714976]: gaps between PE/COFF sections?
Signing Unsigned original image
# echo $?
0
# sbverify --cert /home/dev/sbsign/uefi-public.pem /tmp/tmp.YC4iYlF8UF/test.img
Segmentation fault (core dumped)