Problem with compatibility between plasticparcels and parcels, and parcels v.3 install

[karinkvale]

I am new to parcels and plastic parcels and installing for the first time. plasticparcels installs successfully using parcels v.4. However, compatibility issues arise when attempting the copernicus tutorial, such as:
ImportError: cannot import name 'JITParticle' from 'parcels' (/Users/.../miniconda3/envs/PLASTICPARCELS/lib/python3.14/site-packages/parcels/init.py)
Seems this is a compatibility issue, so I have tried unsuccessfully to install parcels v.3.1.4 using:
conda install conda-forge::parcels==3.1.4
The install appears to hang for hours, stuck on "Solving environment:"
Any advice is appreciated!

[erikvansebille]

Thanks for reaching out, @karinkvale! Good point about the mismatch with Parcels v4. I checked, and while we did have an upper pin in the pyproject.toml (see below), this upper pint was missing in the conda-forge recipe

plasticparcels/pyproject.toml

Line 27 in ccf6c71

"parcels >= 3.0.2, < 4",

I have now also added that upper pin in conda-forge/plasticparcels-feedstock#18. Could you try again to install plasticparcels via condo (perhaps as a fresh install)?

[karinkvale]

Hmm thank you but it is still downloading parcels 4 for some reason, even with a fresh install. Best wishes, Karin

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On 7 Nov 2026, at 3:31 AM, Erik van Sebille ***@***.***> wrote: Thanks for reaching out, @karinkvale <https://github.com/karinkvale>! Good point about the mismatch with Parcels v4. I checked, and while we did have an upper pin in the pyproject.toml (see below), this upper pint was missing in the conda-forge recipe https://github.com/Parcels-code/plasticparcels/blob/ccf6c7186c3a12fb8db311301518fb620c56d73b/pyproject.toml#L27 I have now also added that upper pin in conda-forge/plasticparcels-feedstock#18 <conda-forge/plasticparcels-feedstock#18>. Could you try again to install plasticparcels via condo (perhaps as a fresh install)? — Reply to this email directly, view it on GitHub <#89?email_source=notifications&email_token=AHGHHKZVBJX7T7V4G74GUQD5XXOFZA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJUGQZDEMJRUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSWGM33PORSXEX3DNRUWG2Y#discussioncomment-19442211>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AHGHHK7JJ6J5J64DXJESFWT5XXOFZAVCNFSNUABIKJSXA33TNF2G64TZHM3TCMJYGY3DMMJYHNCGS43DOVZXG2LPNY5TCMJSGM3DKOBRUF3AE>. Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS <https://github.com/notifications/mobile/ios/AHGHHK63OPQLZBPRWC6MGL35XXOFZA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJUGQZDEMJRUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSVGM33PORSXEX3JN5ZQ> and Android <https://github.com/notifications/mobile/android/AHGHHK4RVL7ZDW36IP2IZL35XXOFZA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJUGQZDEMJRUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSXGM33PORSXEX3BNZSHE33JMQ>. Download it today! You are receiving this because you were mentioned.

[erikvansebille]

Strange, because these should now be pinned. Could you copy-paste your entire command history when trying to install plasticparcels here? That will help me dive into the issue a bit deeper

[karinkvale]

Sure- conda remove --name PLASTICPARCELS —all conda create --name PLASTICPARCELS conda activate PLASTICPARCELS conda install conda-forge::plasticparcels conda list parcels # Name Version Build Channel parcels 4.0.2 pyh7c35ba6_0 conda-forge plasticparcels 0.4.0 pyhcf101f3_0 conda-forge Thank you! K

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On 9 Nov 2026, at 5:04 AM, Erik van Sebille ***@***.***> wrote: Strange, because these should now be pinned. Could you copy-paste your entire command history when trying to install plasticparcels here? That will help me dive into the issue a bit deeper — Reply to this email directly, view it on GitHub <#89?email_source=notifications&email_token=AHGHHK5AARHQFKQFYWW6OPL5YCKQ5A5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJUG42TIMZZUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSWGM33PORSXEX3DNRUWG2Y#discussioncomment-19475439>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AHGHHK54RQFVILCN7MT7ZC35YCKQ5AVCNFSNUABIKJSXA33TNF2G64TZHM3TCMJYGY3DMMJYHNCGS43DOVZXG2LPNY5TCMJSGM3DKOBRUF3AE>. Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS <https://github.com/notifications/mobile/ios/AHGHHK2YY6WVELGV4OP23QT5YCKQ5A5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJUG42TIMZZUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSVGM33PORSXEX3JN5ZQ> and Android <https://github.com/notifications/mobile/android/AHGHHK2W4UTX645EASYZBB35YCKQ5A5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJUG42TIMZZUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSXGM33PORSXEX3BNZSHE33JMQ>. Download it today! You are receiving this because you were mentioned.

[erikvansebille]

This is very strange, because if I do exactly the same commands on my macOS system, I get

conda remove --name PLASTICPARCELS —all
conda create --name PLASTICPARCELS
conda activate PLASTICPARCELS
conda install conda-forge::plasticparcels
conda list parcels

# Name                     Version          Build            Channel           
parcels                    3.1.0            pyh6fe113f_1     conda-forge       
plasticparcels             0.4.0            pyh5ded981_2     conda-forge       

So conda picks up the 3.1.0 version of parcels in my case

Which version of conda do you have? I have

conda --version

conda 26.7.3

In how much hurry are you? I wanted to work on updating this plasticparcels package to support Parcels v4.0 in the coming days/weeks anyways Can you wait a week or so more?

[karinkvale]

OK I just upgraded my conda to 26.9.4 and still have this problem. I will soon be overseas until first week of December and not working on this further until my return, so no problem waiting a bit for a solution! Thanks! Karin

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On 9 Nov 2026, at 8:50 PM, Erik van Sebille ***@***.***> wrote: This is very strange, because if I do exactly the same commands on my macOS system, I get conda remove --name PLASTICPARCELS —all conda create --name PLASTICPARCELS conda activate PLASTICPARCELS conda install conda-forge::plasticparcels conda list parcels # Name Version Build Channel parcels 3.1.0 pyh6fe113f_1 conda-forge plasticparcels 0.4.0 pyh5ded981_2 conda-forge So conda picks up the 3.1.0 version of parcels in my case Which version of conda do you have? I have conda --version conda 26.7.3 In how much hurry are you? I wanted to work on updating this plasticparcels package to support Parcels v4.0 in the coming days/weeks anyways Can you wait a week or so more? — Reply to this email directly, view it on GitHub <#89?email_source=notifications&email_token=AHGHHK2XIRO6WUCGHYJU5PT5YFZLRA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJUHA3DMMRSUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSWGM33PORSXEX3DNRUWG2Y#discussioncomment-19486622>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AHGHHK3YZIXV3WNUUI5MYHT5YFZLRAVCNFSNUABIKJSXA33TNF2G64TZHM3TCMJYGY3DMMJYHNCGS43DOVZXG2LPNY5TCMJSGM3DKOBRUF3AE>. Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS <https://github.com/notifications/mobile/ios/AHGHHK65AQMWL7QEL3IZ7LL5YFZLRA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJUHA3DMMRSUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSVGM33PORSXEX3JN5ZQ> and Android <https://github.com/notifications/mobile/android/AHGHHK4JFWPMM3A5OHN7J435YFZLRA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJUHA3DMMRSUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSXGM33PORSXEX3BNZSHE33JMQ>. Download it today! You are receiving this because you were mentioned.

[karinkvale]

Hi again, It worked after I deleted and re-installed conda. Problem solved. Thank you! K

…

On 9 Nov 2026, at 8:50 PM, Erik van Sebille ***@***.***> wrote: This is very strange, because if I do exactly the same commands on my macOS system, I get conda remove --name PLASTICPARCELS —all conda create --name PLASTICPARCELS conda activate PLASTICPARCELS conda install conda-forge::plasticparcels conda list parcels # Name Version Build Channel parcels 3.1.0 pyh6fe113f_1 conda-forge plasticparcels 0.4.0 pyh5ded981_2 conda-forge So conda picks up the 3.1.0 version of parcels in my case Which version of conda do you have? I have conda --version conda 26.7.3 In how much hurry are you? I wanted to work on updating this plasticparcels package to support Parcels v4.0 in the coming days/weeks anyways Can you wait a week or so more? — Reply to this email directly, view it on GitHub <#89?email_source=notifications&email_token=AHGHHK2XIRO6WUCGHYJU5PT5YFZLRA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJUHA3DMMRSUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSWGM33PORSXEX3DNRUWG2Y#discussioncomment-19486622>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AHGHHK3YZIXV3WNUUI5MYHT5YFZLRAVCNFSNUABIKJSXA33TNF2G64TZHM3TCMJYGY3DMMJYHNCGS43DOVZXG2LPNY5TCMJSGM3DKOBRUF3AE>. Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS <https://github.com/notifications/mobile/ios/AHGHHK65AQMWL7QEL3IZ7LL5YFZLRA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJUHA3DMMRSUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSVGM33PORSXEX3JN5ZQ> and Android <https://github.com/notifications/mobile/android/AHGHHK4JFWPMM3A5OHN7J435YFZLRA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJUHA3DMMRSUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSXGM33PORSXEX3BNZSHE33JMQ>. Download it today! You are receiving this because you were mentioned.

[erikvansebille]

Great to hear - glad it worked out!