antsApplyTransform doesn't print reason for missing arg error w/o verbosity level

[toomanycats]

Operating system and version

CentOS 7

CPU architecture

x86_64 (PC, Intel Mac, other Intel/AMD)

ANTs code version

2.5.0.post12-g9516f51

ANTs installation type

Compiled from source

Summary of the problem

I'm learning to use the antsApplyTransform command line program. I left out the argument for a reference image and received no warning or other output. I had to echo $? to find out it failed explicitly. Then I ran again with -v and got the error message that I forgot the -r argument.

I think all programs should report why they failed and make it more obvious.
Thanks !

Commands to reproduce the problem.

antsApplyTransforms -d 3 -i foo.nii.gz -o foo_warped.nii.gz -n NearestNeighbor -t bar_xfm.mat

Output of the command with verbose output.

ANTSVERSION=ants-2.5.0
Using double precision for computations.
Input scalar image: foo.nii.gz
A reference image is required.

Data to reproduce the problem

No special data is required.

[cookpa]

I'm not sure I can implement this becasue non-verbose output was suppressed for compatibility with ANTsR. I would like to always print on error but I think CRAN had different rules.

[gdevenyi]

I'm not sure I can implement this becasue non-verbose output was suppressed for compatibility with ANTsR.

Shouldn't this be handled properly if errors go to stderr instead of stdout?