PackagesNotFoundError: The following packages are not available from current channels

[VictorPoreeFr]

I attempted to install the program Larch using the following commands :
conda create -y --name xraylarch python>=3.13.9
conda activate xraylarch
conda install -y -c conda-forge numpy scipy matplotlib h5py>=3.10 wxpython>=4.2.2 mkl_fft

I get an error message about mkl_fft. So I tried to install it following the ml_fft recommendations but get the same message :

$ conda install -c https://software.repos.intel.com/python/conda mkl_fft
2 channel Terms of Service accepted
Channels:

• https://software.repos.intel.com/python/conda
• defaults
  Platform: osx-arm64
  Collecting package metadata (repodata.json): done
  Solving environment: failed

PackagesNotFoundError: The following packages are not available from current channels:

• mkl_fft

Current channels:

• https://software.repos.intel.com/python/conda
• defaults

[antonwolfy]

@VictorPoreeFr, I'm afraid there is no mkl_fft package for osx-arm64 platform:

$ conda search mkl_fft --platform osx-arm64 -c https://software.repos.intel.com/python/conda -c conda-forge
Loading channels: done
No match found for: mkl_fft. Search: *mkl_fft*

PackagesNotFoundError: The following packages are not available from current channels:

  - mkl_fft

Current channels:

  - https://software.repos.intel.com/python/conda/osx-arm64
  - https://software.repos.intel.com/python/conda/noarch
  - https://conda.anaconda.org/conda-forge/osx-arm64
  - https://conda.anaconda.org/conda-forge/noarch

To search for alternate channels that may provide the conda package you're
looking for, navigate to

    https://anaconda.org

and use the search bar at the top of the page.

Only for osx-64 and only on conda-forge channel:

$ conda search mkl_fft=2.1.2 --platform osx-64 -c https://software.repos.intel.com/python/conda -c conda-forge
Loading channels: done
# Name                       Version           Build  Channel
mkl_fft                        2.1.2 py310h86d4220_0  conda-forge
mkl_fft                        2.1.2 py311hd2046da_0  conda-forge
mkl_fft                        2.1.2 py312h9819111_0  conda-forge
mkl_fft                        2.1.2 py313ha10710d_0  conda-forge
mkl_fft                        2.1.2 py314h42581af_0  conda-forge

[VictorPoreeFr]

Ok thank you. Can I expect one to be available in the future ?

[antonwolfy]

I need to clarify that it actually depends on OSX support for mkl package.

mkl_fft depends on mkl package, like in example:

$ conda search mkl_fft --platform osx-64 --info
...
mkl_fft 2.1.2 py314h42581af_0
-----------------------------
file name   : mkl_fft-2.1.2-py314h42581af_0.conda
name        : mkl_fft
version     : 2.1.2
build       : py314h42581af_0
build number: 0
size        : 161 KB
license     : BSD-3-Clause
subdir      : osx-64
url         : https://conda.anaconda.org/conda-forge/osx-64/mkl_fft-2.1.2-py314h42581af_0.conda
md5         : d349f24e2253ae28c87ceb78ec6739e9
timestamp   : 2025-12-19 18:52:34 UTC
dependencies:
  - __osx >=10.13
  - mkl >=2023.2.0,<2024.0a0
  - mkl-service
  - numpy >=1.23,<3
  - python >=3.14,<3.15.0a0
  - python_abi 3.14.* *_cp314

The dependency mkl >=2023.2.0,<2024.0a0 is placed here that way, because 2023.2 was the last release when MKL provided support for the osx-64 platform:

Starting with the 2024.0 release, macOS is no longer supported in Intel® oneAPI Toolkits and components.

While osx-amd64 platform was never supported by any MKL release. This is the reason mkl_fft can't provide that as well.

I'm afraid I'm not aware if there is any plan to resume OSX support for the MKL.