Error when starting R console after launching Positron

[strengejacke]

System details:

Positron and OS details:

Positron Version: 2025.01.0 (system setup) build 152
Code - OSS Version: 1.95.0
Commit: 66aa3fb
Date: 2025-01-06T02:53:20.465Z
Electron: 32.2.1
Chromium: 128.0.6613.186
Node.js: 20.18.0
V8: 12.8.374.38-electron.0
OS: Windows_NT x64 10.0.26100

Interpreter details:

R 4.4.2

Describe the issue:

When I started Positron, the R console did not launch and I got following error:

The "restart" button did not work, but I could shut down and restart the R console then.

[juliasilge]

Related to #5337

Have you seen this error only once? Or multiple times?

Are you able to share the logs from the "Kernel Supervisor"? Like here:

[strengejacke]

Only once. Will report the output from the logs when I see it again

[e-kotov]

If that helps, here's what I get on a Windows machine:

That's me starting Positron and trying to restart R kernel twice:

R 4.4.0 starting.
Kallichore server did not start after 4653ms

R 4.4.0 restarting.
Kallichore server did not start after 3409ms

R 4.4.0 restarting.
Kallichore server did not start after 4311ms

That's what's going on in the output:

2025-01-08 19:47:02.885 [info] Positron Kernel Supervisor activated
2025-01-08 19:47:02.885 [info] Starting Kallichore server c:\Users\user1\AppData\Local\Programs\Positron\resources\app\extensions\positron-supervisor\resources\kallichore\kcserver.exe on port 42983
Waiting for Kallichore server to start (attempt 1, 3633ms)
Waiting for Kallichore server to start (attempt 6, 3904ms)
Waiting for Kallichore server to start (attempt 11, 4171ms)
Waiting for Kallichore server to start (attempt 16, 4438ms)
Kallichore server did not start after 4653ms
Failed to start Kallichore server: Error: Kallichore server did not start after 4653ms
Starting Kallichore server c:\Users\user1\AppData\Local\Programs\Positron\resources\app\extensions\positron-supervisor\resources\kallichore\kcserver.exe on port 61669
Waiting for Kallichore server to start (attempt 1, 2401ms)
Waiting for Kallichore server to start (attempt 6, 2666ms)
Waiting for Kallichore server to start (attempt 11, 2931ms)
Waiting for Kallichore server to start (attempt 16, 3196ms)
Kallichore server did not start after 3409ms
Starting Kallichore server c:\Users\user1\AppData\Local\Programs\Positron\resources\app\extensions\positron-supervisor\resources\kallichore\kcserver.exe on port 43275
Waiting for Kallichore server to start (attempt 1, 3308ms)
Waiting for Kallichore server to start (attempt 6, 3571ms)
Waiting for Kallichore server to start (attempt 11, 3835ms)
Waiting for Kallichore server to start (attempt 16, 4101ms)
Kallichore server did not start after 4311ms

That's on build

Positron Version: 2025.01.0 (user setup) build 39
Code - OSS Version: 1.93.0
Commit: c7ef34fc7078ac7ecf13ff3328605dfba93f3eea
Date: 2024-12-09T02:49:42.315Z
Electron: 30.4.0
Chromium: 124.0.6367.243
Node.js: 20.15.1
V8: 12.4.254.20-electron.0
OS: Windows_NT x64 10.0.17763

UPDTE: in this build, kcserver.exe is NOT quarantined by F-Secure/WithSecure.

With the latest 2025.01.0 (system setup) build 152 I get the #5905 .
UPDATE: In this build kcserver.exe is quarantined by F-Secure/WithSecure.

[ntluong95]

It sometimes also happen to me, both with R or Python console

[e-kotov]

Latest Windows build (2025.01.0-159) - server is not quarantined by antivirus (as in #5905), but the server does not start on Microsoft Windows Server Version 1809 (OS Build 17763.6659).

Console:

R 4.4.0 starting.
Kallichore server did not start after 3743ms

R 4.4.0 restarting.
Kallichore server did not start after 4138ms

R 4.4.0 restarting.
Kallichore server did not start after 3469ms

Output log

2025-01-10 11:36:36.684 [info] Positron Kernel Supervisor activated
2025-01-10 11:36:36.684 [info] Starting Kallichore server c:\Users\user1\AppData\Local\Programs\Positron\resources\app\extensions\positron-supervisor\resources\kallichore\kcserver.exe on port 63488
Waiting for Kallichore server to start (attempt 1, 2731ms)
Waiting for Kallichore server to start (attempt 6, 2996ms)
Waiting for Kallichore server to start (attempt 11, 3262ms)
Waiting for Kallichore server to start (attempt 16, 3528ms)
Kallichore server did not start after 3743ms
Failed to start Kallichore server: Error: Kallichore server did not start after 3743ms
Starting Kallichore server c:\Users\user1\AppData\Local\Programs\Positron\resources\app\extensions\positron-supervisor\resources\kallichore\kcserver.exe on port 55710
Waiting for Kallichore server to start (attempt 1, 3089ms)
Waiting for Kallichore server to start (attempt 6, 3366ms)
Waiting for Kallichore server to start (attempt 11, 3660ms)
Waiting for Kallichore server to start (attempt 16, 3923ms)
Kallichore server did not start after 4138ms
Starting Kallichore server c:\Users\user1\AppData\Local\Programs\Positron\resources\app\extensions\positron-supervisor\resources\kallichore\kcserver.exe on port 59247
Waiting for Kallichore server to start (attempt 1, 2385ms)
Waiting for Kallichore server to start (attempt 6, 2662ms)
Waiting for Kallichore server to start (attempt 11, 2961ms)
Waiting for Kallichore server to start (attempt 16, 3258ms)
Kallichore server did not start after 3469ms

But running the kcserver.exe manually gets me this:

So I guess it is able to run...

Let me know if you need anything else to debug this.

[juliasilge]

If we get more reports of this, we can try out #5800 as an option to mitigate these kinds of challenges with Windows machine configuration.

[strengejacke]

I have similar problems with Kallichore on Windows. On my laptop, there was a security note. On my PC at home and office, no security alert, but same problem: Kallichore did not start.

[nmambre]

In my case, the last build I can use is Positron-2025.01.0-39. With the newer versions I get the Kallichore error. I can always restart manually, and then run R code, but in that case the variable pane doesn't show the variables, only 3 dots. Is this issue with the variable pane related or is it something else? Any way I can manually refresh the contents of the variable pane? The Refresh objects doesn't do anything.

Positron Version: 2025.02.0 (system setup) build 79
Code - OSS Version: 1.96.0
Commit: a268bc86f313a0e454069790b1cbaadebc74262b
Date: 2025-01-21T02:49:15.664Z
Electron: 32.2.6
Chromium: 128.0.6613.186
Node.js: 20.18.1
V8: 12.8.374.38-electron.0
OS: Windows_NT x64 10.0.19045

2025-01-26 00:02:22.084 [info] Positron Kernel Supervisor activated
2025-01-26 00:02:22.085 [info] Kallichore server PID 1588 is not running
2025-01-26 00:02:22.085 [info] Could not reconnect to Kallichore server at http://localhost:45940. Starting a new server
2025-01-26 00:02:22.085 [info] Starting Kallichore server c:\Program Files\Positron\resources\app\extensions\positron-supervisor\resources\kallichore\kcserver.exe on port 58973
Waiting for Kallichore server to start (attempt 1, 2869ms)
Waiting for Kallichore server to start (attempt 6, 3187ms)
Waiting for Kallichore server to start (attempt 11, 3511ms)
Waiting for Kallichore server to start (attempt 16, 3809ms)
Kallichore server did not start after 4183ms
Failed to start Kallichore server: Error: Kallichore server did not start after 4183ms
Kallichore server PID 1588 is not running
Could not reconnect to Kallichore server at http://localhost:45940. Starting a new server
Starting Kallichore server c:\Program Files\Positron\resources\app\extensions\positron-supervisor\resources\kallichore\kcserver.exe on port 59414
Waiting for Kallichore server to start (attempt 1, 360ms)
Kallichore 0.1.27 server online with 0 sessions
Kallichore server started in 554ms

[reuning]

I'm getting this on MacOS.

Positron Version: 2025.02.0 (Universal) build 79
Code - OSS Version: 1.96.0
Commit: a268bc86f313a0e454069790b1cbaadebc74262b
Date: 2025-01-21T02:44:54.581Z
Electron: 32.2.6
Chromium: 128.0.6613.186
Node.js: 20.18.1
V8: 12.8.374.38-electron.0
OS: Darwin arm64 24.2.0

2025-01-30 10:26:28.099 [info] Positron Kernel Supervisor activated
2025-01-30 10:26:28.099 [info] Starting Kallichore server /Applications/Positron.app/Contents/Resources/app/extensions/positron-supervisor/resources/kallichore/kcserver on port 47358
2025-01-30 10:26:28.099 [info] Waiting for Kallichore server to start (attempt 1, 352ms)
Waiting for Kallichore server to start (attempt 6, 612ms)
Waiting for Kallichore server to start (attempt 11, 879ms)
Waiting for Kallichore server to start (attempt 16, 1156ms)
Kallichore server did not start after 1378ms
Failed to start Kallichore server: Error: Kallichore server did not start after 1378ms
Supervisor terminal closed unexpectedly; output:
/Applications/Positron.app/Contents/Resources/app/extensions/positron-supervisor/resources/kallichore/kcserver --port 47358 --token /var/folders/bv/5q08600s2cz3c5fsqf125rfc0000gq/T/kallichore-61513468.token --log-level debug --log-file /var/folders/bv/5q08600s2cz3c5fsqf125rfc0000gq/T/kallichore-61513468.log --idle-shutdown-hours 1
 
  ,            _   _           _                    
 /|   /       | | | | o       | |                   
  |__/   __,  | | | |     __  | |     __   ,_    _  
  | \   /  |  |/  |/  |  /    |/ \   /  \_/  |  |/  
  |  \_/\_/|_/|__/|__/|_/\___/|   |_/\__/    |_/|__/
  A Jupyter Kernel supervisor. Version 0.1.27.
  Copyright (c) 2025, Posit Software PBC. All rights reserved.

Listening at 127.0.0.1:47358
15:26:29 �[0m�[34m[INFO] �[0mStarting Kallichore server at 127.0.0.1:47358
15:26:29 �[0m�[34m[INFO] �[0mServer set to shut down after 1 hours of inactivity

2025-01-30 10:26:36.178 [info] Positron Kernel Supervisor activated
2025-01-30 10:26:36.182 [info] Starting Kallichore server /Applications/Positron.app/Contents/Resources/app/extensions/positron-supervisor/resources/kallichore/kcserver on port 50106
Waiting for Kallichore server to start (attempt 1, 110ms)
Waiting for Kallichore server to start (attempt 6, 368ms)
Waiting for Kallichore server to start (attempt 11, 629ms)
Waiting for Kallichore server to start (attempt 16, 898ms)
Kallichore server did not start after 1117ms
Failed to start Kallichore server: Error: Kallichore server did not start after 1117ms

Edit: After submitting this I then tried restarting R again and it worked. I had tried opening and closing Positron entirely a few times and had this appear each time.

[jmcphers]

I can't reproduce this but you might be seeing #6129, which we have fixed in newer builds (not yet public).

[juliasilge]

We have a new release with some improved Kallichore behavior, as well as hopefully better error logging:
https://github.com/posit-dev/positron/releases/tag/2025.02.0-137

If those of you in this issue who have experienced this category of problems are willing to try a new build, we definitely are interested in further feedback!

[e-kotov]

If those of you in this issue who have experienced this category of problems are willing to try a new build, we definitely are interested in further feedback!

Latest build for Windows now works fine for me without antivirus quarantines or other issues.

[strengejacke]

For me, too, didn't see this issue yet (running on three different computers)

[nmambre]

This latest build has been starting up correctly for me (Windows 10).

[reuning]

Loaded it up and so far no problems. Thanks!

[juliasilge]

Oh WOW, this is fantastic news! 🎉 Our fix for #6129 was somewhat speculative so this is really great to hear.

I am going to close this issue but thank you again for the reports and please do let us know if you see further problems.