HTTP 400 when resolving packages using pixi on Mac when installed from conda-forge (>0.45.0)

[millsks]

Opening a discussion before opening an issue.

We are currently getting Pixi approved for use internally. In the meantime, we are installing Pixi from conda-forge. We have not seen this issue on Linux or Windows, but on Mac we get a HTTP 400 whenever we create or update the lock file.

We tried different versions of Pixi from conda-forge and had to downgrade all the way to 0.45.0 before it started to work again.

I tried installing Pixi in the Minforge base environment and also in an environment all by itself.

When I run pixi install -vvvv or pixi lock -vvvv for pixi>=0.46.0 on Mac when installed using conda from conda-forge I will see the HTTP 400 when it tries to solve requirements for an environment. The trace message is referencing rattler_repodata_gateway::fetch::with_cache when trying to fetch repodata.json.

We are not seeing this issue on Linux or Windows.

We are also not seeing this for Mac IF we get Pixi straight from the GitHub asset section of the Pixi release.

[millsks]

I am behind a corporate network otherwise I would have posted the trace output of the commands.

One other tidbit I can add is that we use Artifactory as a remote proxy for conda-forge due to firewalls blocking access to conda-forge on conda.anaconda.org and prefix.dev's hosted mirrors too.

[wolfv]

Can you see on which URL it gives the 400? I assume on the repodata.json.zst or repodata.json?

One difference is that we might use rustls-tls on our own builds, and openssl on the conda-forge ones.

[millsks]

It is erroring out on https://artifactory-server001/artifactory/api/conda/conda-forge-remote/osx-64/repodata.json

We tried updating our default channel to a few different Artifactory instances that we have running.

[millsks]

Was there any big difference between after 0.45? If we are using 0.45 from conda-forge we do not seem to hit the issue.

[millsks]

Unfortunately I did not get anywhere when I got home. I tried installing Pixi from conda-forge on my personal laptop and I did not hit the same issue. I am wondering if there is something with how Pixi is talking to Artifactory with TLS in the new versions built for conda-forge.

Troubleshooting Pixi HTTP 400 error on Mac OS X when installed from conda-forge

Conda version information

❯ conda info

     active environment : base
    active env location : /Users/millsks/miniforge3/24.11.3-2
            shell level : 1
       user config file : /Users/millsks/.condarc
 populated config files : /Users/millsks/miniforge3/24.11.3-2/.condarc
                          /Users/millsks/.condarc
          conda version : 24.11.3
    conda-build version : not installed
         python version : 3.12.9.final.0
                 solver : libmamba (default)
       virtual packages : __archspec=1=m1
                          __conda=24.11.3=0
                          __osx=15.6=0
                          __unix=0=0
       base environment : /Users/millsks/miniforge3/24.11.3-2  (writable)
      conda av data dir : /Users/millsks/miniforge3/24.11.3-2/etc/conda
  conda av metadata url : None
           channel URLs : https://conda.anaconda.org/conda-forge/osx-arm64
                          https://conda.anaconda.org/conda-forge/noarch
          package cache : /Users/millsks/UserLocal/conda/pkgs
       envs directories : /Users/millsks/UserLocal/conda/envs
                          /Users/millsks/miniforge3/24.11.3-2/envs
                          /Users/millsks/.conda/envs
               platform : osx-arm64
             user-agent : conda/24.11.3 requests/2.32.3 CPython/3.12.9 Darwin/24.6.0 OSX/15.6 solver/libmamba conda-libmamba-solver/24.9.0 libmambapy/1.5.12
                UID:GID : 501:20
             netrc file : None
           offline mode : False

Install Pixi into a new environment

❯ conda create -n pixi pixi
Retrieving notices: done
Channels:
 - defaults
Platform: osx-arm64
Collecting package metadata (repodata.json): done
Solving environment: done


==> WARNING: A newer version of conda exists. <==
    current version: 24.11.3
    latest version: 25.7.0

Please update conda by running

    $ conda update -n base -c defaults conda



## Package Plan ##

  environment location: /Users/millsks/UserLocal/conda/envs/pixi

  added / updated specs:
    - pixi


The following packages will be downloaded:

    package                    |            build
    ---------------------------|-----------------
    pixi-0.51.0                |       hdfb9898_0        22.2 MB  defaults
    ------------------------------------------------------------
                                           Total:        22.2 MB

The following NEW packages will be INSTALLED:

  libcxx             conda-forge/osx-arm64::libcxx-20.1.8-hf598326_1
  pixi               conda-forge/osx-arm64::pixi-0.51.0-hdfb9898_0



Downloading and Extracting Packages:

Preparing transaction: done
Verifying transaction: done
Executing transaction: done
#
# To activate this environment, use
#
#     $ conda activate pixi
#
# To deactivate an active environment, use
#
#     $ conda deactivate

❯ conda deactivate
❯ conda activate pixi
❯ conda info

     active environment : pixi
    active env location : /Users/millsks/UserLocal/conda/envs/pixi
            shell level : 1
       user config file : /Users/millsks/.condarc
 populated config files : /Users/millsks/miniforge3/24.11.3-2/.condarc
                          /Users/millsks/.condarc
          conda version : 24.11.3
    conda-build version : not installed
         python version : 3.12.9.final.0
                 solver : libmamba (default)
       virtual packages : __archspec=1=m1
                          __conda=24.11.3=0
                          __osx=15.6=0
                          __unix=0=0
       base environment : /Users/millsks/miniforge3/24.11.3-2  (writable)
      conda av data dir : /Users/millsks/miniforge3/24.11.3-2/etc/conda
  conda av metadata url : None
           channel URLs : https://conda.anaconda.org/conda-forge/osx-arm64
                          https://conda.anaconda.org/conda-forge/noarch
          package cache : /Users/millsks/UserLocal/conda/pkgs
       envs directories : /Users/millsks/UserLocal/conda/envs
                          /Users/millsks/miniforge3/24.11.3-2/envs
                          /Users/millsks/.conda/envs
               platform : osx-arm64
             user-agent : conda/24.11.3 requests/2.32.3 CPython/3.12.9 Darwin/24.6.0 OSX/15.6 solver/libmamba conda-libmamba-solver/24.9.0 libmambapy/1.5.12
                UID:GID : 501:20
             netrc file : None
           offline mode : False

❯ conda list
# packages in environment at /Users/millsks/UserLocal/conda/envs/pixi:
#
# Name                    Version                   Build  Channel
libcxx                    20.1.8               hf598326_1    defaults
pixi                      0.51.0               hdfb9898_0    defaults

❯ command -v pixi
/Users/millsks/UserLocal/conda/envs/pixi/bin/pixi

Create new Pixi project

❯ cd UserLocal/apps/src/code/Public-Git/millsks
❯ mkdir hello-pixi
❯ cd hello-pixi
❯ pixi init
✔ Created /Users/millsks/UserLocal/apps/src/code/Public-Git/millsks/hello-pixi/pixi.toml
❯ cat pixi.toml
[workspace]
authors = ["Kevin Mills <[email protected]>"]
channels = ["conda-forge"]
name = "hello-pixi"
platforms = ["osx-arm64"]
version = "0.1.0"

[tasks]

[dependencies]

❯ pixi add pip
✔ Added pip >=25.2,<26
❯ pixi add python=3.12
✔ Added python=3.12
❯ pixi info
System
------------
       Pixi version: 0.51.0
           Platform: osx-arm64
   Virtual packages: __unix=0=0
                   : __osx=15.6=0
                   : __archspec=1=m1
          Cache dir: /Users/millsks/Library/Caches/rattler/cache
       Auth storage: /Users/millsks/.rattler/credentials.json
   Config locations: No config files found

Global
------------
            Bin dir: /Users/millsks/.pixi/bin
    Environment dir: /Users/millsks/.pixi/envs
       Manifest dir: /Users/millsks/.pixi/manifests/pixi-global.toml

Workspace
------------
               Name: hello-pixi
            Version: 0.1.0
      Manifest file: /Users/millsks/UserLocal/apps/src/code/Public-Git/millsks/hello-pixi/pixi.toml
       Last updated: 13-08-2025 15:27:13

Environments
------------
        Environment: default
           Features: default
           Channels: conda-forge
   Dependency count: 2
       Dependencies: pip, python
   Target platforms: osx-arm64
    Prefix location: /Users/millsks/UserLocal/apps/src/code/Public-Git/millsks/hello-pixi/.pixi/envs/default

❯ pixi list
Package          Version   Build               Size       Kind   Source
bzip2            1.0.8     h99b78c6_7          120 KiB    conda  https://conda.anaconda.org/conda-forge/
ca-certificates  2025.8.3  hbd8a1cb_0          150.8 KiB  conda  https://conda.anaconda.org/conda-forge/
icu              75.1      hfee45f7_0          11.3 MiB   conda  https://conda.anaconda.org/conda-forge/
libexpat         2.7.1     hec049ff_0          64.4 KiB   conda  https://conda.anaconda.org/conda-forge/
libffi           3.4.6     h1da3d7d_1          38.9 KiB   conda  https://conda.anaconda.org/conda-forge/
liblzma          5.8.1     h39f12f2_2          90.1 KiB   conda  https://conda.anaconda.org/conda-forge/
libsqlite        3.50.4    h4237e3c_0          881.5 KiB  conda  https://conda.anaconda.org/conda-forge/
libzlib          1.3.1     h8359307_2          45.3 KiB   conda  https://conda.anaconda.org/conda-forge/
ncurses          6.5       h5e97a16_3          778.3 KiB  conda  https://conda.anaconda.org/conda-forge/
openssl          3.5.2     he92f556_0          2.9 MiB    conda  https://conda.anaconda.org/conda-forge/
pip              25.2      pyh8b19718_0        1.1 MiB    conda  https://conda.anaconda.org/conda-forge/
python           3.12.11   hc22306f_0_cpython  12.4 MiB   conda  https://conda.anaconda.org/conda-forge/
readline         8.2       h1d1bf99_2          246.4 KiB  conda  https://conda.anaconda.org/conda-forge/
setuptools       80.9.0    pyhff2d567_0        731.2 KiB  conda  https://conda.anaconda.org/conda-forge/
tk               8.6.13    h892fb3f_2          3 MiB      conda  https://conda.anaconda.org/conda-forge/
tzdata           2025b     h78e105d_0          120.1 KiB  conda  https://conda.anaconda.org/conda-forge/
wheel            0.45.1    pyhd8ed1ab_1        61.5 KiB   conda  https://conda.anaconda.org/conda-forge/


❯ pixi tree
├── python 3.12.11
│   ├── __osx
│   ├── bzip2 1.0.8
│   │   └── __osx  (*)
│   ├── libexpat 2.7.1
│   │   └── __osx  (*)
│   ├── libffi 3.4.6
│   │   └── __osx  (*)
│   ├── liblzma 5.8.1
│   │   └── __osx  (*)
│   ├── libsqlite 3.50.4
│   │   ├── __osx  (*)
│   │   ├── icu 75.1
│   │   │   └── __osx  (*)
│   │   └── libzlib 1.3.1
│   │       └── __osx  (*)
│   ├── libzlib 1.3.1 (*)
│   ├── ncurses 6.5
│   │   └── __osx  (*)
│   ├── openssl 3.5.2
│   │   ├── __osx  (*)
│   │   └── ca-certificates 2025.8.3
│   │       └── __unix
│   ├── readline 8.2
│   │   └── ncurses 6.5 (*)
│   ├── tk 8.6.13
│   │   ├── __osx  (*)
│   │   └── libzlib 1.3.1 (*)
│   └── tzdata 2025b
└── pip 25.2
    ├── python 3.12.11 (*)
    ├── setuptools 80.9.0
    │   └── python 3.12.11 (*)
    └── wheel 0.45.1
        └── python 3.12.11 (*)

❯ pixi install -vvvv
TRACE pixi_manifest::discovery: Found manifest in directory: "/Users/millsks/UserLocal/apps/src/code/Public-Git/millsks/hello-pixi", continuing further.
DEBUG pixi_config: Loading config from /etc/pixi/config.toml
DEBUG pixi_config: Loading config from /Users/millsks/Library/Application Support/pixi/config.toml
DEBUG pixi_config: Loading config from /Users/millsks/.pixi/config.toml
DEBUG pixi_config: Loading config from /Users/millsks/UserLocal/apps/src/code/Public-Git/millsks/hello-pixi/.pixi/config.toml
DEBUG pixi_config: Failed to load local config: /Users/millsks/UserLocal/apps/src/code/Public-Git/millsks/hello-pixi/.pixi/config.toml (error: no file was found at /Users/millsks/UserLocal/apps/src/code/Public-Git/millsks/hello-pixi/.pixi/config.toml)
DEBUG pixi::environment: verifying prefix location is unchanged, with prefix file: /Users/millsks/UserLocal/apps/src/code/Public-Git/millsks/hello-pixi/.pixi/envs/conda-meta/pixi_env_prefix
TRACE rattler_networking::s3_middleware: Creating S3 middleware using {}
TRACE pixi_command_dispatcher::command_dispatcher_processor: Dispatch background task has started
TRACE pixi::lock_file::package_identifier: Using backwards compatibility purl logic for conda package: bzip2
TRACE pixi::lock_file::package_identifier: Using backwards compatibility purl logic for conda package: ca-certificates
TRACE pixi::lock_file::package_identifier: Using backwards compatibility purl logic for conda package: icu
TRACE pixi::lock_file::package_identifier: Using backwards compatibility purl logic for conda package: libexpat
TRACE pixi::lock_file::package_identifier: Using backwards compatibility purl logic for conda package: libffi
TRACE pixi::lock_file::package_identifier: Using backwards compatibility purl logic for conda package: liblzma
TRACE pixi::lock_file::package_identifier: Using backwards compatibility purl logic for conda package: libsqlite
TRACE pixi::lock_file::package_identifier: Using backwards compatibility purl logic for conda package: libzlib
TRACE pixi::lock_file::package_identifier: Using backwards compatibility purl logic for conda package: ncurses
TRACE pixi::lock_file::package_identifier: Using backwards compatibility purl logic for conda package: openssl
TRACE pixi::lock_file::package_identifier: Using backwards compatibility purl logic for conda package: pip
TRACE pixi::lock_file::package_identifier: Using backwards compatibility purl logic for conda package: python
TRACE pixi::lock_file::package_identifier: Using backwards compatibility purl logic for conda package: readline
TRACE pixi::lock_file::package_identifier: Using backwards compatibility purl logic for conda package: setuptools
TRACE pixi::lock_file::package_identifier: Using backwards compatibility purl logic for conda package: tk
TRACE pixi::lock_file::package_identifier: Using backwards compatibility purl logic for conda package: tzdata
TRACE pixi::lock_file::package_identifier: Using backwards compatibility purl logic for conda package: wheel
 INFO pixi::lock_file::update: the lock-file is up-to-date
DEBUG pixi::lock_file::virtual_packages: Required virtual packages of environment 'default': __osx >=11.0, __unix, __osx >=11.0
DEBUG pixi::lock_file::virtual_packages: Generic system virtual packages for env: 'default' : [__unix: __unix=0=0, __archspec: __archspec=1=m1, __osx: __osx=15.6=0]
DEBUG pixi::lock_file::virtual_packages: Required virtual package: __osx >=11.0 matches the system
DEBUG pixi::lock_file::virtual_packages: Skipping virtual package: __unix as it's not in the accepted packages
DEBUG pixi::lock_file::virtual_packages: Required virtual package: __osx >=11.0 matches the system
DEBUG pixi::environment::conda_prefix: updating prefix for 'default'
DEBUG pixi::rlimit: Increased RLIMIT_NOFILE to 1024
DEBUG rattler_conda_types::repo_data::topological_sort: Breaking cycle: {}
 INFO pixi::environment::conda_metadata: No update needed for the prefix file.
DEBUG pixi::environment::conda_metadata: Verify history file exists: /Users/millsks/UserLocal/apps/src/code/Public-Git/millsks/hello-pixi/.pixi/envs/default/conda-meta/history
DEBUG pixi::lock_file::resolve::uv_resolution_context: uv keyring provider is disabled
DEBUG pixi::activation: Running activation script for Default
 INFO pixi::lock_file::update: Installed environment 'default' in 14.916542ms
DEBUG pixi::environment: Wrote environment file to: "/Users/millsks/UserLocal/apps/src/code/Public-Git/millsks/hello-pixi/.pixi/envs/default/conda-meta/pixi"
✔ The default environment has been installed.
TRACE pixi_command_dispatcher::command_dispatcher_processor: Dispatch background task has finished