Regression between v1.2.2 and release-2.0.0rc1: caput type on pv.DISP generates a warning `[setter error] put returned 'Invalid element count requested'`

[vnadot]

The following wetest script generates a warning [setter error] put returned 'Invalid element count requested' in release-2.0.0rc1 whereas in v1.2.2 it was not the case.

version: {major: 1, minor: 2, bugfix: 2} # don't forget to change version

config:
  name: "test"
  on_failure: continue

tests:
  # enable put
  - name: "enable PV put"
    commands:
    - name:       "enable PV put (DISP EPICS field)"
      setter:     "SL-SCL-CM1:RF-RFFI-1:GenDriverScanSet.DISP"
      set_value:  0

    - name:       "enable PV put (DISP EPICS field)"
      setter:     "SL-SCL-CM1:RF-RFFI-1:GenDriverScanSet.DISP"
      set_value:  "0"

in v1.2.2: no warning

$ WeTest/ ((v2.0.0rc1))
$ git tag
v1.0.0
v1.2.2
v2.0.0rc1
$ WeTest/ ((v2.0.0rc1))
$ git checkout v1.0.0
Previous HEAD position was e5ab8fb Merge pull request #73 from epics-extensions/release-2.0.0rc1
HEAD is now at 8b627d8 closes #47 non-zero return code with --version
$ WeTest/ ((v1.2.2))
$ virtualenv --python=/usr/bin/python2.7 venv
Running virtualenv with interpreter /usr/bin/python2.7
New python executable in /.../venv/bin/python2.7
Also creating executable in /.../venv/bin/python
Installing setuptools, pip, wheel...done.
$ WeTest/ ((v1.2.2))
$ source ./venv/bin/activate 
$ WeTest/ ((v1.2.2))
$ pip install .
...
Successfully installed Pillow-6.2.2 PyYAML-5.4.1 colorlog-4.8.0 docopt-0.6.2 numpy-1.16.0 pyepics-3.4.3 pykwalify-1.7.0 python-dateutil-2.9.0.post0 reportlab-3.5.55 six-1.16.0 wetest-1.2.2
You are using pip version 9.0.1, however version 24.0 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
$ wetest bug.yaml
File incompatible with reader of installed WeTest.
File format version is: 2.0.0, but wetest version is: 1.2.2
$ WeTest/ ((v1.2.2))
$ wetest bug.yaml
Validation of YAML scenario file: /home/vnadot/.../bug.yaml
Loaded 2 tests from `WeTest Suite`:
	- functional (ordered)  `test`
PV changed to connected: SL-SCL-CM1:RF-RFFI-1:GenDriverScanSet.DISP
-----------------------
Ready to start testing, use GUI play button.
Applying selection may take some time.

Running    test-0-0-0    enable PV put: enable PV put (DISP EPICS field)
Success of test-0-0-0    (in 1.050s) 

Running    test-0-0-1    enable PV put: enable PV put (DISP EPICS field)
Success of test-0-0-1    (in 1.002s) 
----------------------------------------------------------------------
Ran 2 tests in 2.054s

OK
Done running tests.
-----------------------
Ready to start testing, use GUI play button.
Done generating report: /.../wetest-results.pdf
GUI closed.
Aborting execution.
Exiting WeTest.

in release-2.0.0rc1: warning because of 'set_value: "0"'

It took me some time to understand the warning. I would say that generally the WeTest messages are not user friendly. I will create a dedicated issue for that (#85).

$ WeTest/dist/wetest-2.0.0rc1-x86_64.AppImage bug.yaml
Validation of YAML scenario file: /.../bug.yaml
Loaded 2 tests from `WeTest Suite`:
	- functional (ordered)  `test`
PV changed to connected: SL-SCL-CM1:RF-RFFI-1:GenDriverScanSet.DISP
Warning: Undefined Behavior!
         Detected use of epicsThread from child process after fork()
-----------------------
Ready to start testing, use GUI play button.
Applying selection may take some time.

Running    test-0-0-0    enable PV put: enable PV put (DISP EPICS field)
Success of test-0-0-0    (in 1.047s) 

Running    test-0-0-1    enable PV put: enable PV put (DISP EPICS field)
Error   of test-0-0-1    (in 0.003s) [setter error]  put returned 'Invalid element count requested'
======================================================================
ERROR: test-0-0-1 (wetest.testing.generator.SelectableTestCase)
enable PV put: enable PV put (DISP EPICS field)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/nix/store/pnkbr2dx35h9rz9zn3fgvcgvfr73smvs-python3.9-wetest-2.0.0rc1/lib/python3.9/site-packages/wetest/testing/generator.py", line 438, in test
    setter.put(set_value)
  File "/iee/extensions/lib/python/pyepics-3.2.4-py2.7.egg/epics/pv.py", line 336, in put
    return ca.put(self.chid, value,
  File "/iee/extensions/lib/python/pyepics-3.2.4-py2.7.egg/epics/ca.py", line 403, in wrapper
    return fcn(*args, **kwds)
  File "/iee/extensions/lib/python/pyepics-3.2.4-py2.7.egg/epics/ca.py", line 1329, in put
    PySEVCHK('put', ret)
  File "/iee/extensions/lib/python/pyepics-3.2.4-py2.7.egg/epics/ca.py", line 432, in PySEVCHK
    raise CASeverityException(func_name, message(status))
epics.ca.CASeverityException:  put returned 'Invalid element count requested'

----------------------------------------------------------------------
Ran 2 tests in 1.155s

FAILED (errors=1)
Done running tests.
Warning: Undefined Behavior!
         Detected use of epicsThread from child process after fork()
-----------------------
Ready to start testing, use GUI play button.
Done generating report: /.../wetest-results.pdf
GUI closed.
Aborting execution.
Exiting WeTest.