cli: broken pipe when piping reana-client list

[diegodelemos]

When running BSM Search demo:

$ reana-client list | head
NAME                                                                        SIZE      LAST-MODIFIED
hepdata/submission.zip                                                      2590      2018-08-08 09:54:50.584332+00:00
plot/postfit.pdf                                                            19439     2018-08-08 09:55:07.913777+00:00
plot/prefit.pdf                                                             19401     2018-08-08 09:55:00.399603+00:00
merge/merged.root                                                           14375     2018-08-08 09:53:21.319798+00:00
_yadage/yadage_snapshot_backend.json                                        19009     2018-08-08 09:55:19.808627+00:00
_yadage/yadage_snapshot_workflow.json                                       1734638   2018-08-08 09:55:19.804632+00:00
_yadage/yadage_template.json                                                33766     2018-08-08 09:40:14.191464+00:00
makews/results/workspace_combined_meas_profileLR.eps                        8475      2018-08-08 09:54:00.981216+00:00
makews/results/workspace_combined_meas_model.root                           71462     2018-08-08 09:53:49.243230+00:00
Something went wrong while retrieving file list for workflow workflow.1:
[Errno 32] Broken pipe
Exception ignored in: <_io.TextIOWrapper name='<stdout>' mode='w' encoding='UTF-8'>
BrokenPipeError: [Errno 32] Broken pipe

[diegodelemos]

This is a known issue which can be easily reproduced with:

$ python -c 'for i in range(10000): print(i)' | head -3
0
1
2
Traceback (most recent call last):
  File "<string>", line 1, in <module>
IOError: [Errno 32] Broken pipe

The only proposed solution is for Python3 (currently we only support 2.7 in client).

[dinosk]

There are some workarounds like:
head -3 <(rc list)
maybe we can write it in the docs

[diegodelemos]

It still shows up. The only way to make it for me is to redirect stderr (reana-client list 2> /dev/null | head -3).

For BSM Search I am going to switch the head for a grep which in the end achieves the same goal and it doesn't crash with this error (reana-client list | grep ".pdf").