simple-scan must be run as super user

[grubenm]

I'm running simple-scan 3.22.0.1-1, build date Sat 01 Oct 2016 01:31:39 PM CDT, installed on an Arch Linux system via the pacman package manager.

As a normal user, the command `simple-scan` returns the following error:
[1] 10855 segmentation fault (core dumped) simple-scan

However, running `sudo simple-scan`, after providing authentication, does not produce the above error, and the simple-scan program appears to run fine.

I am able to run `xsane` as a normal user without error.

simple-scan --debug > simple-scan.log 2>&1 produces an empty file, and the following output to the console:
[1] 11018 segmentation fault (core dumped) simple-scan --debug > /tmp/simple-scan.log 2>&1

My scanner is a Canon Pixma MP560, which is connected to my home network via its onboard WiFi, though simple-scan fails to start regardless of whether that scanner is on or off.

[Robert Ancell (robert-ancell)]

Since this is not occurring for me and might be driver dependant I would need a stacktrace of the crash. Are you able to make one?

[grubenm (grubenm)]

Hey Robert,

I'd be happy to generate a stacktrace, but unfortunately I'm not sure how.

Below is my guessed attempt from within gdb, using version simple-scan-3.24.0 that I built locally from the tarball just now following the README.md (this version also generates a segmentation fault for me, if I ./simple-scan).

(gdb) run
Starting program: /tmp/simple-scan-3.24.0/install/bin/simple-scan
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/libthread_db.so.1".

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff3c3584c in vfprintf () from /usr/lib/libc.so.6
(gdb) bt
#0 0x00007ffff3c3584c in vfprintf () at /usr/lib/libc.so.6
#1 0x00007ffff3c3ddd4 in fprintf () at /usr/lib/libc.so.6
#2 0x000000000041d57d in simple_scan_log_cb (log_domain=<optimized out>, message=0x79b100 "simple-scan.vala:674: Starting Simple Scan 3.24.0, PID=12736", log_level=<optimized out>)
    at /home/bob/bzr/simple-scan/trunk/src/simple-scan.vala:533
#3 0x000000000041d57d in _simple_scan_log_cb_glog_func (log_domain=<optimized out>, log_levels=<optimized out>, message=0x79b100 "simple-scan.vala:674: Starting Simple Scan 3.24.0, PID=12736", self=<optimized out>)
    at /home/bob/bzr/simple-scan/trunk/src/simple-scan.vala:672
#4 0x00007ffff5322374 in g_logv () at /usr/lib/libglib-2.0.so.0
#5 0x00007ffff532257f in g_log () at /usr/lib/libglib-2.0.so.0
#6 0x000000000041ea42 in simple_scan_main (args=<optimized out>, args_length1=<optimized out>)
    at /home/bob/bzr/simple-scan/trunk/src/simple-scan.vala:674
#7 0x00007ffff3c0d511 in __libc_start_main () at /usr/lib/libc.so.6
#8 0x000000000040eeda in _start ()

If this isn't what you were after, I'm happy to try some other approach.

Thanks for your willingness to help out on this

[grubenm (grubenm)]

I was able to fix this issue by changing the permissions of ~/.cache to [user]:[group] rather than root:root.

As such, this issue appears to be idiosyncratic to my own setup, and not indicative of issues within simple-scan.

Thanks again for your help!