added '-s' option in example command

[bhargavthriler]

Description The pytest -s option is required to read from stdin.

Checklist

• [x] PR has been tested

[codecov[bot]]

Codecov Report

Merging #447 (35d79ba) into master (44be6b0) will increase coverage by 4.9%. The diff coverage is n/a.

@@           Coverage Diff            @@
##           master    #447     +/-   ##
========================================
+ Coverage    56.4%   61.3%   +4.9%     
========================================
  Files         116     135     +19     
  Lines        7161   11339   +4178     
========================================
+ Hits         4039    6958   +2919     
- Misses       3122    4381   +1259     

Impacted Files	Coverage Δ
labgrid/util/helper.py	63.1% <0.0%> (-21.6%)	:arrow_down:
labgrid/driver/usbloader.py	46.6% <0.0%> (-11.9%)	:arrow_down:
labgrid/strategy/shellstrategy.py	41.1% <0.0%> (-8.9%)	:arrow_down:
labgrid/driver/quartushpsdriver.py	37.8% <0.0%> (-4.8%)	:arrow_down:
labgrid/driver/usbvideodriver.py	28.7% <0.0%> (-4.6%)	:arrow_down:
labgrid/driver/onewiredriver.py	87.0% <0.0%> (-3.9%)	:arrow_down:
labgrid/driver/serialdigitaloutput.py	50.0% <0.0%> (-3.4%)	:arrow_down:
labgrid/util/expect.py	91.6% <0.0%> (-2.5%)	:arrow_down:
labgrid/pytestplugin/fixtures.py	63.2% <0.0%> (-2.4%)	:arrow_down:
labgrid/util/proxy.py	76.3% <0.0%> (-2.0%)	:arrow_down:
... and 87 more

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[jluebbe]

As the transitions are executed under with capsys.disabled():, the -s switch should not be needed. Is that broken for you?

[Emantor]

Yes, see #443

[jluebbe]

@Emantor, according to https://docs.pytest.org/en/latest/capture.html#accessing-captured-output-from-a-test-function, it should be possible to disable capturing with capsys.disabled(). If that's broken, we should fix it upstream instead of using -s as a workaround.

[Emantor]

pytest-dev/pytest#2189 seems to indicate that we are not alone. Only stdout is not captured, stdin looks to be captured even with capsys.disabled(). I'll look into pytest and determine whether this can be fixed there or we need to have a workaround within labgrid.

[jluebbe]

The capsys docs now refer explicitly to stdout/stderr, so we need to document using -s in the example and with ManualPowerDriver under pytest.