# Mamba fails to create environment because the \`--yes\` flag is not supplied

**URL:** <https://community.seqera.io/t/mamba-fails-to-create-environment-because-the-yes-flag-is-not-supplied/2118>\
**Category:** Ask for help\
**Tags:** nextflow\
**Created:** [May 9, 2025, 7:00pm UTC](https://community.seqera.io/t/mamba-fails-to-create-environment-because-the-yes-flag-is-not-supplied/2118 "2025-05-09T19:00:26Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![Ariel\_Schwartz](https://dub1.discourse-cdn.com/flex013/user_avatar/community.seqera.io/ariel_schwartz/32/1799_2.png) [@Ariel\_Schwartz](https://community.seqera.io/u/Ariel_Schwartz)\
**Post date:** [May 9, 2025, 7:00pm UTC](https://community.seqera.io/t/mamba-fails-to-create-environment-because-the-yes-flag-is-not-supplied/2118/1 "2025-05-09T19:00:26Z")

</div>

Mamba fails to create environment because the `--yes` flag is not supplied.  
Adding `conda.createOptions = '--yes'` does not help either.

```auto
  Failed to create Conda environment
    command: mamba env create --prefix ./work/conda/env-961b98c89213eaa1-e6f0bafd6827065b938c2602e5e8feef --file ./envs/seqkit_env.yaml
    status : 143
...
      ─────────────────────────────────────────────────────────────────────────────
      
      
      Confirm changes: [Y/n]

 -- Check '.nextflow.log' file for details

```

---

<div class="post-metadata">

**Author:** ![yinshiyi](https://dub1.discourse-cdn.com/flex013/user_avatar/community.seqera.io/yinshiyi/32/1091_2.png) [@yinshiyi](https://community.seqera.io/u/yinshiyi)\
**Post date:** [June 23, 2025, 6:19pm UTC](https://community.seqera.io/t/mamba-fails-to-create-environment-because-the-yes-flag-is-not-supplied/2118/2 "2025-06-23T18:19:44Z")

</div>

My team is dealing with the exact same error.  
The solution is to downgrade back to \<=mamba=1.5.11  
Mamba 2.0 upgrade changed the interactive module and nextflow 24 is still assuming the same connection to mamba as conda. they are mostly the same. (but might not be the case for mamba\>=2.0)  
Here is another reference from another team: [mamba env create stalls · Issue #5625 · nextflow-io/nextflow · GitHub](https://github.com/nextflow-io/nextflow/issues/5625)

* * *

Update July 7th, this issue should be resolved:

[https://github.com/nextflow-io/nextflow/pull/6248](https://github.com/nextflow-io/nextflow/pull/6248)

---

<div class="post-metadata">

**Author:** ![ewels](https://dub1.discourse-cdn.com/flex013/user_avatar/community.seqera.io/ewels/32/1_2.png) [@ewels](https://community.seqera.io/u/ewels)\
**Post date:** [July 10, 2025, 10:57pm UTC](https://community.seqera.io/t/mamba-fails-to-create-environment-because-the-yes-flag-is-not-supplied/2118/3 "2025-07-10T22:57:25Z")

</div>

This fix was merged in [Fix mamba env create stalls at prompt [ci fast] · nextflow-io/nextflow@e7c9379 · GitHub](https://github.com/nextflow-io/nextflow/commit/e7c937910fb9e6471c71f4feb509e3139b56d0b0) and is available in the `v25.06.0-edge` release and onwards.

---

<div class="post-metadata">

**Author:** ![system](https://dub1.discourse-cdn.com/flex013/user_avatar/community.seqera.io/system/32/2402_2.png) [@system](https://community.seqera.io/u/system)\
**Post date:** [July 17, 2025, 10:59pm UTC](https://community.seqera.io/t/mamba-fails-to-create-environment-because-the-yes-flag-is-not-supplied/2118/4 "2025-07-17T22:59:16Z")

</div>

Closed on July 17, 2025, 10:59pm UTC

This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.