`genie_python` Troubleshooting

Logging

Where are the logs?

Genie_python writes its logs to C:\Instrument\var\logs\genie_python.

What does `ERROR: CAException` mean when it is in the log?

The following is written to the log when a virtual circuit disconnects from the IOC side:

    2018-05-21T15:21:31	(CA)	(15712)	ERROR: CAException: type=-1 state=192 op=5 file=..\cac.cpp lineNo=1223
    2018-05-21T15:21:31	(CA)	(15712)	ERROR: CAException: type=6 state=192 op=0 file=..\getCopy.cpp lineNo=92

The time stamp on these are for the first get_pv call or equivalent after a disconnect.

Command problems

Can not set or get a block reports disconnected

There can be multiple problems, check:

Block exists
Block is spelt correctly, use b. and autocomplete
Try getting the underlying PV g.get_pv("IN:<instrument>:CS:SB:<Block name?")
Restart the GUI genie_python console

Import problems

Can’t find Python 3

If you get an error message similar to

*** Cannot find GENIE-PYTHON 3 - some things are not likely to work ***

on running config_env.bat, you need to ensure you have Python 3 available on your system.

Other Issues

Can not set change users

Users seems not to get set properly using g.change_users, see ticket 5812. Look into this it is more than a one off.

Repeated error messages in console while waiting

If you get repeated errors of the form:

2020-11-11T17:20:48	(CMD)	(17808)	2020-11-11 17:20:48.374781: Exception in waitfor loop: UnableToConnectToPVException: Unable to connect to PV IN:LARMOR:DAE:GOODUAH: does not exist
2020-11-11T17:20:48	(CMD)	(17808)	2020-11-11 17:20:48.512496: Exception cleared

You may need to restart the genie_python session. The root cause of this issue is currently unknown. See ticket 5893 for details, including a script which can scan all instruments for occurrences of this issue. If this issue is seen again, please create a new ticket to investigate further and also link it here.

can read local PVs from instrument but not e.g. `CS:INSTLIST` or accelerator ones like beam current

In one case this was due to the firewall rule for A:\python3\python.exe had been disabled - a process firewall exception is needed to allow it to receive the UDP name query reply

Can’t import channel-access modules

If you get an error of the form:

Traceback (most recent call last):
  File "c:\Jenkins\workspace\System_Tests\test_genie_python_common_imports.py", line 33, in _attempt_to_import_module_by_name
    mod = importlib.import_module(module_name)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Instrument\Apps\Python3\Lib\importlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 1204, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1176, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1147, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 690, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 940, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "C:\Instrument\Apps\Python3\Lib\site-packages\setuptools_dso\__init__.py", line 10, in <module>
    from .dsocmd import DSO, Extension, install, build, build_dso, build_ext, bdist_egg
  File "C:\Instrument\Apps\Python3\Lib\site-packages\setuptools_dso\dsocmd.py", line 729, in <module>
    _needs_builddso(_build, right_before='build_clib')
  File "C:\Instrument\Apps\Python3\Lib\site-packages\setuptools_dso\dsocmd.py", line 715, in _needs_builddso
    assert issubclass(command, Command)

When trying to import channel access libraries (CaChannel, pcaspy, aioca, p4p etc), this may be because import pip has previously been run in the same python session. See https://github.com/pypa/pip/issues/8761 for some details/links. import pip is not generally supported/recommended by python and is a bad idea - if wanting to install packages dynamically, use subprocess instead to explicitly spawn a new process which calls pip.

It’s also technically possible to replace import pip with:

import _distutils_hack
_distutils_hack.remove_shim()
import pip

But this is not recommended for obvious reasons.

Pyright completely fails to run

Pyright keeps a cache directory in c:\Users\<user>\.cache\pyright-python, this can get corrupted, if it does get corrupted pyright will entirely fail to execute. This cache directory can be deleted (at the cost of the next script-check operation being much slower).

Error from g.load_script will be a json.decoder.JSONDecodeError as pyright does not return JSON in this case (but rather, returns some non-JSON error message).

genie_python Troubleshooting