# Python Script ocassionally throws errors

**URL:** <https://forum.knime.com/t/python-script-ocassionally-throws-errors/60364>\
**Category:** Feedback & Ideas\
**Tags:** bug\
**Created:** [January 25, 2023, 12:00pm UTC](https://forum.knime.com/t/python-script-ocassionally-throws-errors/60364 "2023-01-25T12:00:37Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![mwiegand](https://forum-cdn.knime.com/user_avatar/forum.knime.com/mwiegand/32/66896_2.png) [@mwiegand](https://forum.knime.com/u/mwiegand)\
**Post date:** [January 25, 2023, 12:00pm UTC](https://forum.knime.com/t/python-script-ocassionally-throws-errors/60364/1 "2023-01-25T12:00:37Z")

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Hi,

I have executed a Python solution but in parallel chunks.

> [@External Tool "issues" and high difficulty to use](https://forum.knime.com/t/external-tool-issues-and-high-difficulty-to-use/58252/12):
>
> Totally agree, we should make the External Tool node more usable. Still, to give you a possible workaround right now, I just rebuilt the NGS Bash node’s functionality using the Python Script node in KNIME 4.7, and using the bundled Python environment (which it’ll use by default if you freshly install the Python Integration in KNIME). So you don’t even need to deal with setting up a Python installation. Place a Python Script node in your workflow, click the three dots to remove the input table …

Occasionally the following error was thrown which I could circumvent by re-execution:

```auto
ERROR Python Script 3:983:0:819:0:853:955 Execute failed: Could not start Python. There are problems with your Python environment:
Python installation could not be determined.xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun

ERROR Python Script 3:983:0:819:0:853:927 Execute failed: Could not start Python. There are problems with your Python environment:
Python installation could not be determined.xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun

ERROR Parallel Chunk End 3:983:0:819:0:783 Execute failed: Not all chunks finished - check individual chunk branches for details.

```

Best  
Mike

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**Author:** ![steffen\_KNIME](https://forum-cdn.knime.com/user_avatar/forum.knime.com/steffen_knime/32/33719_2.png) [@steffen\_KNIME](https://forum.knime.com/u/steffen_KNIME)\
**Post date:** [January 26, 2023, 3:34pm UTC](https://forum.knime.com/t/python-script-ocassionally-throws-errors/60364/2 "2023-01-26T15:34:16Z")

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Hi Mike,

unfortunately, this seems to be an issue related to Apple according to the following links.  
Could you try the first (or other) links suggestion with `xcode-select --install`?

> <https://apple.stackexchange.com/questions/254380/why-am-i-getting-an-invalid-active-developer-path-when-attempting-to-use-git-a>

> <https://stackoverflow.com/questions/64489433/xcrun-error-invalid-active-developer-path-problem-after-zsh-update-for-flutte>

> <https://stackoverflow.com/questions/52522565/git-is-not-working-after-macos-update-xcrun-error-invalid-active-developer-pa>

Edit: a link with even more solution possibilities

> **[\[SOLVED\] Mac OS: xcrun: error: invalid active developer path, missing xcrun -...](https://www.studytonight.com/post/solved-mac-os-xcrun-error-invalid-active-developer-path-missing-xcrun)**
>
> Fix for xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun error in MacOS due to Xcode not available.

Best regards  
Steffen

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<div class="post-metadata">

**Author:** ![mwiegand](https://forum-cdn.knime.com/user_avatar/forum.knime.com/mwiegand/32/66896_2.png) [@mwiegand](https://forum.knime.com/u/mwiegand)\
**Post date:** [January 28, 2023, 8:39am UTC](https://forum.knime.com/t/python-script-ocassionally-throws-errors/60364/3 "2023-01-28T08:39:55Z")

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Thanks a lot for your suggestions @steffen_KNIME. I have worked through these and going to pay attention if the erratic issue still occurs. Enjoy your weekend!

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**Author:** ![system](https://forum-cdn.knime.com/uploads/default/original/1X/ab3ccf34482a0329361734a18199390177204f15.png) [@system](https://forum.knime.com/u/system)\
**Post date:** [April 28, 2023, 8:40am UTC](https://forum.knime.com/t/python-script-ocassionally-throws-errors/60364/4 "2023-04-28T08:40:02Z")

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<div class="post-metadata">

**Author:** ![ScottF](https://forum-cdn.knime.com/user_avatar/forum.knime.com/scottf/32/61316_2.png) [@ScottF](https://forum.knime.com/u/ScottF)\
**Post date:** [May 18, 2023, 2:52pm UTC](https://forum.knime.com/t/python-script-ocassionally-throws-errors/60364/5 "2023-05-18T14:52:13Z")

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