Created attachment 1146301 [details]
convert with multiple conflicting log

Description of problem:
Virt-v2v can't show any error notification to user when using virt-v2v convert a guest with multiple conflicting for "-oa"


Version-Release number of selected component (if applicable):

virt-v2v-1.32.3-1.el7.x86_64
libguestfs-1.32.3-1.el7.x86_64
libvirt-1.3.3-1.el7.x86_64
qemu-kvm-1.5.3-109.el7.x86_64


How reproducible:
100%

Steps to Reproduce:

1.Convert a guest with multiple conflicting option "-oa" from local to rhevm  using virt-v2v 
#virt-v2v -o rhev -os 10.73.2.1:/home/nfs_export -of raw rhel6.6 -oa sparse -n ovirtmgmt -oa sparse -oa preallocated  -oa sparse

Actual results:
1,There is no error notification to user on the command line 
## virt-v2v -o rhev -os 10.73.2.1:/home/nfs_export -of raw rhel6.6 -oa sparse -n ovirtmgmt -oa sparse -oa preallocated  -oa sparse 
[   0.0] Opening the source -i libvirt rhel6.6
[   0.0] Creating an overlay to protect the source from being modified
[   0.4] Initializing the target -o rhev -os 10.73.2.1:/home/nfs_export
virt-v2v: warning: cannot write files to the NFS server as 36:36, even 
though we appear to be running as root. This probably means the NFS client 
or idmapd is not configured properly.

You will have to chown the files that virt-v2v creates after the run, 
otherwise RHEV-M will not be able to import the VM.
[   0.5] Opening the overlay
[   5.0] Inspecting the overlay
[  17.1] Checking for sufficient free disk space in the guest
[  17.1] Estimating space required on target for each disk
[  17.1] Converting Red Hat Enterprise Linux Server release 6.6 (Santiago) to run on KVM
virt-v2v: This guest has virtio drivers installed.
[  79.5] Mapping filesystem data to avoid copying unused and blank areas
[  79.8] Closing the overlay
[  80.0] Checking if the guest needs BIOS or UEFI to boot
[  80.0] Assigning disks to buses
[  80.0] Copying disk 1/1 to /tmp/v2v.p2TQIT/7786f4e5-b04e-44e4-b909-363566201ffa/images/19a608ad-8dba-486b-b118-4e7bf775246e/47a1e159-3205-4cc3-a373-0fb59809f2be (raw)
    (100.00/100%)
[ 136.6] Creating output metadata
[ 136.7] Finishing off

2,The latest "-oa " output will be execute  

Expected results:
virt-v2v should be prevent the multiple conflicting for "-oa", and give to user a error notification, like below notification:

virt-v2v: error: -on option used more than once on the command line

If reporting bugs, run virt-v2v with debugging enabled and include the 
complete output:

  virt-v2v -v -x [...]


Additional info:
The guest which convert with multiple conflicting for "-oa" can be boot and meet all checkpoint