[Libguestfs] guestfs_launch gets stuck

[Richard W.M. Jones]

On Mon, Aug 29, 2016 at 08:24:43PM +0800, Baochuan Wu wrote:
> Hello everyone,
> 
> I am using libguestfs on CentOS 7.2. I am trying to modify Red Hat 5.4
> disks. I am using C/C++. I found the process gets stuck
> inside guestfs_launch:
> 
> Thread 1 (Thread 0x7fe3aa6148c0 (LWP 1265)):
> #0  0x00007fe3a9032c20 in __poll_nocancel () from /lib64/libc.so.6
> #1  0x00007fe3aa1e5ea4 in read_data () from /lib64/libguestfs.so.0
> #2  0x00007fe3aa20af0c in guestfs_int_recv_from_daemon () from
> /lib64/libguestfs.so.0
> #3  0x00007fe3aa204ae0 in launch_libvirt () from /lib64/libguestfs.so.0
> #4  0x00007fe3aa1fab2b in guestfs_impl_launch () from /lib64/libguestfs.so.0
> #5  0x00007fe3aa196b4d in guestfs_launch () from /lib64/libguestfs.so.0
> #6  0x00000000004116f8 in main ()

Before you call guestfs_launch(), call:

  guestfs_set_verbose (1);
  guestfs_set_trace (1);

That should print (on stderr) a lot more information about what is
going on. (http://libguestfs.org/guestfs-faq.1.html#how-do-i-debug-when-using-the-api)

If printing on stderr is not convenient from your program, then you
can also set up logging.  See the example here:

https://github.com/libguestfs/libguestfs/blob/master/examples/debug-logging.c

The libguestfs-test-tool output looks fine BTW.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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