(WIP) Try conditional dependencies

[jaimergp]

Trying conda/rattler#1816

Only for CLI inputs now:

pixi run conda create -dnx  --solver=rattler -c conda-forge --override-channels --debug "python; if __linux"

[jaimergp]

I don't think the conditions are being used in the solver. The above command results in a successful Python solve on my macbook, and it shouldn't because __linux is not there.

See logs:

DEBUG conda.conda_rattler_solver.solver:_solve_attempt(350): Solver input:
{
  "constraints": [],
  "locked_packages": [],
  "pinned_packages": [],
  "specs": [
    "python; if __linux"
  ]
}
...
INFO conda.core.link:__init__(217): initializing UnlinkLinkTransaction with
  target_prefix: /Users/jrodriguez/devel/conda-rattler-solver/.pixi/envs/default/envs/x
  unlink_precs:
    
  link_precs:
    conda-forge/osx-arm64::bzip2-1.0.8-hd037594_8
    conda-forge/noarch::ca-certificates-2025.11.12-hbd8a1cb_0
    conda-forge/osx-arm64::icu-75.1-hfee45f7_0
    conda-forge/osx-arm64::libexpat-2.7.3-haf25636_0
    conda-forge/osx-arm64::libffi-3.5.2-he5f378a_0
    conda-forge/osx-arm64::liblzma-5.8.1-h39f12f2_2
    conda-forge/osx-arm64::libmpdec-4.0.0-h5505292_0
    conda-forge/osx-arm64::libzlib-1.3.1-h8359307_2
    conda-forge/osx-arm64::ncurses-6.5-h5e97a16_3
    conda-forge/noarch::python_abi-3.14-8_cp314
    conda-forge/noarch::tzdata-2025b-h78e105d_0
    conda-forge/osx-arm64::libsqlite-3.51.0-h8adb53f_0
    conda-forge/osx-arm64::openssl-3.6.0-h5503f6c_0
    conda-forge/osx-arm64::readline-8.2-h1d1bf99_2
    conda-forge/osx-arm64::tk-8.6.13-h892fb3f_3
    conda-forge/osx-arm64::zstd-1.5.7-h6491c7d_2
    conda-forge/osx-arm64::python-3.14.0-h40d2674_102_cp314

[jaimergp]

Another example, this should not bring numpy in:

$ pixi run conda create -dnx "python=3.10" "numpy; if python>=3.12" --solver=rattler -c conda-forge --override-channels
Channel: conda-forge
Platform: osx-arm64
Target prefix: /Users/jrodriguez/devel/conda-rattler-solver/.pixi/envs/default/envs/x
Collecting package metadata (repodata.json): done
Solving environment: done

## Package Plan ##

  environment location: /Users/jrodriguez/devel/conda-rattler-solver/.pixi/envs/default/envs/x

  added / updated specs:
    - numpy; if python>=3.12
    - python=3.10


The following packages will be downloaded:

    package                    |            build
    ---------------------------|-----------------
    bzip2-1.0.8                |       hd037594_8         122 KB  conda-forge
    ca-certificates-2025.11.12 |       hbd8a1cb_0         149 KB  conda-forge
    icu-75.1                   |       hfee45f7_0        11.3 MB  conda-forge
    libblas-3.11.0             |2_h51639a9_openblas          18 KB  conda-forge
    libcblas-3.11.0            |2_hb0561ab_openblas          18 KB  conda-forge
    libcxx-21.1.6              |       hf598326_0         556 KB  conda-forge
    libexpat-2.7.3             |       haf25636_0          66 KB  conda-forge
    libffi-3.5.2               |       he5f378a_0          39 KB  conda-forge
    libgfortran-15.2.0         |       hfcf01ff_1         131 KB  conda-forge
    libgfortran5-15.2.0        |       h742603c_1         746 KB  conda-forge
    liblapack-3.11.0           |2_hd9741b5_openblas          18 KB  conda-forge
    liblzma-5.8.1              |       h39f12f2_2          90 KB  conda-forge
    libopenblas-0.3.30         |openmp_ha158390_3         4.1 MB  conda-forge
    libsqlite-3.51.0           |       h8adb53f_0         888 KB  conda-forge
    libzlib-1.3.1              |       h8359307_2          45 KB  conda-forge
    llvm-openmp-21.1.6         |       h4a912ad_0         279 KB  conda-forge
    ncurses-6.5                |       h5e97a16_3         778 KB  conda-forge
    numpy-2.2.6                |  py310h4d83441_0         5.6 MB  conda-forge
    openssl-3.6.0              |       h5503f6c_0         3.0 MB  conda-forge
    python-3.10.19             |hcd7f573_2_cpython        11.1 MB  conda-forge
    python_abi-3.10            |          8_cp310           7 KB  conda-forge
    readline-8.2               |       h1d1bf99_2         246 KB  conda-forge
    tk-8.6.13                  |       h892fb3f_3         3.0 MB  conda-forge
    tzdata-2025b               |       h78e105d_0         120 KB  conda-forge
    ------------------------------------------------------------
                                           Total:        42.3 MB

The following NEW packages will be INSTALLED:

  bzip2              conda-forge/osx-arm64::bzip2-1.0.8-hd037594_8 
  ca-certificates    conda-forge/noarch::ca-certificates-2025.11.12-hbd8a1cb_0 
  icu                conda-forge/osx-arm64::icu-75.1-hfee45f7_0 
  libblas            conda-forge/osx-arm64::libblas-3.11.0-2_h51639a9_openblas 
  libcblas           conda-forge/osx-arm64::libcblas-3.11.0-2_hb0561ab_openblas 
  libcxx             conda-forge/osx-arm64::libcxx-21.1.6-hf598326_0 
  libexpat           conda-forge/osx-arm64::libexpat-2.7.3-haf25636_0 
  libffi             conda-forge/osx-arm64::libffi-3.5.2-he5f378a_0 
  libgfortran        conda-forge/osx-arm64::libgfortran-15.2.0-hfcf01ff_1 
  libgfortran5       conda-forge/osx-arm64::libgfortran5-15.2.0-h742603c_1 
  liblapack          conda-forge/osx-arm64::liblapack-3.11.0-2_hd9741b5_openblas 
  liblzma            conda-forge/osx-arm64::liblzma-5.8.1-h39f12f2_2 
  libopenblas        conda-forge/osx-arm64::libopenblas-0.3.30-openmp_ha158390_3 
  libsqlite          conda-forge/osx-arm64::libsqlite-3.51.0-h8adb53f_0 
  libzlib            conda-forge/osx-arm64::libzlib-1.3.1-h8359307_2 
  llvm-openmp        conda-forge/osx-arm64::llvm-openmp-21.1.6-h4a912ad_0 
  ncurses            conda-forge/osx-arm64::ncurses-6.5-h5e97a16_3 
  numpy              conda-forge/osx-arm64::numpy-2.2.6-py310h4d83441_0 
  openssl            conda-forge/osx-arm64::openssl-3.6.0-h5503f6c_0 
  python             conda-forge/osx-arm64::python-3.10.19-hcd7f573_2_cpython 
  python_abi         conda-forge/noarch::python_abi-3.10-8_cp310 
  readline           conda-forge/osx-arm64::readline-8.2-h1d1bf99_2 
  tk                 conda-forge/osx-arm64::tk-8.6.13-h892fb3f_3 
  tzdata             conda-forge/noarch::tzdata-2025b-h78e105d_0 



DryRunExit: Dry run. Exiting.