FAHClient throws exception (Fedora 26)

[fhew]

I just upgraded to version 7.6.9 and when the FAHControl is running, the FAHClient emits the following message
onto its stdout/stderr every 2-3 seconds:

17:52:10:ERROR:std::exception: std::bad_cast

And stopping FAHClient quiets FAHControl.

Fortunately, everything else seems to work.
(Running on Fedora 26.)

[Jesse_V]

Hi fhew and welcome to the forum.

This is an unusual error message. Can you please post more of the log? (please wrap it in Code tags) That we we have more details on where this error is coming from.

[fhew]

There is nothing unusual in the log.
It and the client proceeds normally.
And as soon as I start FAHControl, and it connects to FAHClient, the client starts
spewing the exception every ~2 seconds.

Stopping FAHControl stops the exception... restarting FAHControl restarts the exception.

Note that having the browser based controller connected does NOT cause the exceptions.

Code: Select all

17:31:15:Trying to access database...
17:31:15:Successfully acquired database lock
17:31:15:Enabled folding slot 00: READY cpu:3
17:31:21:WU00:FS00:Connecting to 65.254.110.245:80
17:31:22:WARNING:WU00:FS00:Failed to get assignment from '65.254.110.245:80': No WUs available for this configuration
17:31:22:WU00:FS00:Connecting to 18.218.241.186:80
17:31:23:ERROR:std::exception: std::bad_cast
17:31:23:WARNING:WU00:FS00:Failed to get assignment from '18.218.241.186:80': No WUs available for this configuration
17:31:23:WU00:FS00:Connecting to 65.254.110.245:80
17:31:23:ERROR:std::exception: std::bad_cast
17:31:23:WU00:FS00:Assigned to work server 168.245.198.125
17:31:23:WU00:FS00:Requesting new work unit for slot 00: READY cpu:3 from 168.245.198.125
17:31:23:WU00:FS00:Connecting to 168.245.198.125:8080
17:31:24:WU00:FS00:Downloading 5.66MiB
17:31:27:ERROR:std::exception: std::bad_cast
17:31:28:ERROR:std::exception: std::bad_cast
17:31:28:17:127.0.0.1:New Web session
17:31:30:WU00:FS00:Download 52.97%
17:31:31:ERROR:std::exception: std::bad_cast
17:31:33:ERROR:std::exception: std::bad_cast
17:31:34:WU00:FS00:Download complete
17:31:34:WU00:FS00:Received Unit: id:00 state:DOWNLOAD error:NO_ERROR project:16420 run:1475 clone:0 gen:39 core:0xa7 unit:0x0000002ba8f5c67d5e8a605cb0dbc1e4
17:31:34:WU00:FS00:Starting
17:31:34:WU00:FS00:Running FahCore: /usr/bin/FAHCoreWrapper /home/fhew/Desktop/oximeter/cores/cores.foldingathome.org/v7/lin/64bit/avx/Core_a7.fah/FahCore_a7 -dir 00 -suffix 01 -version 706 -lifeline 25759 -checkpoint 15 -np 3
17:31:34:WU00:FS00:Started FahCore on PID 25799
17:31:35:WU00:FS00:Core PID:25804
17:31:35:WU00:FS00:FahCore 0xa7 started
17:31:35:ERROR:std::exception: std::bad_cast

[fhew]

More information:

1/ It turns out that FAHViewer ALSO causes FAHClient to throw the same exception
A set of 3 exceptions every 5 seconds.
In this case, so as to not confuse symptoms, I started the FAHViewer directly without using
FAHControl (Because FAHControl on it own causes Client to throw the exceptions.)

2/ The Viewer never does render the molecule.
I used Wireshark to sniff the conversation between the Client and the Viewer when the viewer starts
and got the following conversation:

Code: Select all

.[H.[2JWelcome to the FAHClient command server.
> updates add 0 5 $heartbeat
updates add 1 5 $slot-info

> 
> 
PyON 1 slots
[
  {
    "id": "00",
    "status": "RUNNING",
    "description": "cpu:3",
    "options": {},
    "reason": "",
    "idle": False
  }
]
---
updates add 2 5 $(simulation-info 0)
updates add 3 5 $(trajectory 0)

> 

[fhew]

I have opened a bug report on GitHub, on this issue (#1411).