ghex unable to open /dev/loop0

[Alexander Sashnov]

ghex is unable to open /dev/loop0 file.

There is no permission problems here:

$ strace -o xxd.strace xxd /dev/loop0 | head
0000000: eb58 9053 5953 4c49 4e55 5800 0208 3004 .X.SYSLINUX...0.
0000010: 0200 0000 00f8 0000 3f00 ff00 3f00 0000 ........?...?...
0000020: 6ade 7700 e81d 0000 0000 0000 0200 0000 j.w.............
0000030: 0100 0600 0000 0000 0000 0000 0000 0000 ................
0000040: 8000 29f6 bcdb 344e 4f20 4e41 4d45 2020 ..)...4NO NAME
0000050: 2020 4641 5433 3220 2020 fafc 31c9 8ed1 FAT32 ..1...
0000060: bc76 7b52 0657 1e56 8ec1 b126 bf78 7bf3 .v{R.W.V...&.x{.
0000070: a58e d9bb 7800 0fb4 370f a056 20d2 781b ....x...7..V .x.
0000080: 31c0 b106 893f 8947 02f3 64a5 8a0e 187c 1....?.G..d....|
0000090: 884d f850 5050 50cd 13eb 628b 55aa 8b75 .M.PPPP...b.U..u
$

$ strace -o ghex ghex /dev/loop0

(ghex:19624): Gtk-CRITICAL **: gtk_main_quit: assertion `main_loops != NULL' failed

(ghex:19624): Gtk-CRITICAL **: gtk_main_quit: assertion `main_loops != NULL' failed
$
(empty ghex window was showed, like when run 'ghex' without any command line option)

* Additional info *

From xxd strace log:
...
open("/dev/loop0", O_RDONLY) = 3
fstat(3, {st_mode=S_IFBLK|0660, st_rdev=makedev(7, 0), ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f73e8fbc000
read(3, "\353X\220SYSLINUX\0\2\0100\4\2\0\0\0\0\370\0\0?\0\377\0?\0\0\0"..., 4096) = 4096
fstat(1, {st_mode=S_IFIFO|0600, st_size=0, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f73e8fbb000
write(1, "0000000: eb58 9053 5953 4c49 4e5"..., 4096) = 4096
write(1, "0000 0000 0000 0000 0000 0000 00"..., 4096) = 4096
...

From ghex strace log:
...
access("/dev/loop0", F_OK) = 0
brk(0xfd1000) = 0xfd1000
access("/etc/gtk-3.0/settings.ini", F_OK) = 0
open("/etc/gtk-3.0/settings.ini", O_RDONLY) = 9
fstat(9, {st_mode=S_IFREG|0644, st_size=176, ...}) = 0
read(9, "[Settings]\ngtk-theme-name = Ambi"..., 4096) = 176
...
getcwd("/home/alex", 4096) = 11
brk(0x119a000) = 0x119a000
stat("/dev/loop0", {st_mode=S_IFBLK|0660, st_rdev=makedev(7, 0), ...}) = 0
write(2, "\n(ghex:19624): Gtk-CRITICAL **: "..., 85) = 85
write(2, "\n(ghex:19624): Gtk-CRITICAL **: "..., 85) = 85
getcwd("/home/alex", 4096) = 11
open("/usr/share/fonts/truetype/ttf-dejavu/DejaVuSans.ttf", O_RDONLY) = 10
...

Both 'strace' logs are attached.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: ghex 3.4.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-37.58-generic 3.2.35
Uname: Linux 3.2.0-37-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu17.2
Architecture: amd64
Date: Fri Apr 26 09:44:21 2013
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ghex
UpgradeStatus: No upgrade log present (probably fresh install)