Core.rush(enable = TRUE) error causes Builder experiment to crash in RUN mode

Builder
1

OS : Mac OS 15.5
PsychoPy version : Initially built and tried in Psychopy 2025.2.1, then re-saved and tried again in 2026.1.3.
Standard Standalone Installation? (y/n): y
Do you want it to also run online? (y/n): y
What are you trying to achieve?: For the experiment to run both in desktop mode and in online mode.

What did you try to make it work?: Saving the experiment copy and running it in the newest Psychopy version

What specifically went wrong when you tried that?: The issue persisted

I have built a simple experiment in Builder with an aim for it to run online in the future. It ran perfectly well in Pilot mode. However, when I turned it into Run mode for a final test, it began crashing straight after measuring the frame rate of screen. It crashes with this error code:

2026-08-10 10:44:44.844 python[60718:39572170] ApplePersistenceIgnoreState: Existing state will not be touched. New state will be written to /var/folders/sp/z10b1nf56xj5qk86bqsfk3p80000gn/T/org.opensciencetools.psychopy.savedState
/Applications/PsychoPy.app/Contents/Resources/lib/python3.10/requests/init.py:86: RequestsDependencyWarning: Unable to find acceptable character detection dependency (chardet or charset_normalizer).
warnings.warn(
Traceback (most recent call last):
File “/Users/evgeniyaanisimova/Library/CloudStorage/OneDrive-Nexus365/ROAR_LDT/LDT_pretest_lastrun.py”, line 3861, in
run(
File “/Users/evgeniyaanisimova/Library/CloudStorage/OneDrive-Nexus365/ROAR_LDT/LDT_pretest_lastrun.py”, line 347, in run
core.rush(enable=True)
TypeError: rush() got an unexpected keyword argument ‘enable’
######## Experiment ended with exit code 1 [pid:60718] #########

From what I can see (please correct me if I’m wrong), the Builder tries to use an outdated rush format (“enable = TRUE” rather than “TRUE”). I am not sure how to go about fixing it as it is not recommended to edit the code behind Builder experiments when the aim is for them to run online.

I do have one custom component in the study (feedback message) - I don’t think that is causing this issue as it’s not related to the rush function, but please let me know if it might be the cause.

Many thanks for all your help!

2

Please could you post the lines surrounding line 347 in the Python file so we can work out what component or code is adding core.rush?

3

I can see the line of code in question (it’s in psychopy.experiment.flow) and this is a bug I think, I’ll get a fix in for the next bugfix release :slight_smile:

4

These are the relevant lines from the lastrun.py file Builder generated:

“”"

enter ‘rush’ mode (raise CPU priority)

if not PILOTING:
core.rush(enable=True)

mark experiment as started

thisExp.status = STARTED

5

Ah, great, thank you! Is there anything you recommend that I do for now to get it to run?

6

For now, you could untick “Enable ‘rush’ mode” in Experiment Settings then add a Code Component with this in the Before Experiment tab:

if not PILOTING:
    core.rush(True)

(this is the code that Builder should, and will after the next bugfix release, be writing)

7

Amazing, thank you so much for your help! Can confirm that it worked (although only if the code is in Begin Experiment, not Before, as otherwise it says “PILOTING” is not defined) :slight_smile: