Conda Troubleshooting#

Before using the troubleshooting below please ensure you are using Mambaforge. Using mamba is preferable over conda as it’s faster and better at resolving dependencies. To install mambaforge please follow this documentation

Issues#

Unable to find mantid or mantidworkbench#

PackagesNotFoundError: The following packages are not available from current channels

If you encounter this error it may be because you have not included the mantid channel in your download command. Please ensure you include -c mantid when installing.

Example

mamba create -n mantid_env -c mantid mantid

You may also encounter this error when trying to install on Apple silicon devices. See Installing on Apple silicon devices for help.

Installing on Apple silicon devices#

On macOS we provide both an Intel (x86) and Apple Silicon (ARM) package from v6.13 onwards. Mamba will automatically determine which package to install based on your device.

The processor in your machine can be found by navigating to the Apple logo -> About This Mac. On an Apple Silicon device, the Chip line will say Apple M then a number indicating the version of the chip on the device. An Intel device will have a Processor line, followed by some details of the specific CPU used in the device.

For versions of mantid prior to v6.13, only x86 packages are available. These can still be used by those with Apple Silicon devices using Rosetta. You will need to have Rosetta installed and precede the mamba commands with CONDA_SUBDIR=osx-64.

For example, if you want to install v6.12 of mantidworkbench, use the following command:

CONDA_SUBDIR=osx-64 mamba create -n mantid_env -c mantid mantidworkbench=6.12

Unable to resolve dependencies#

If you are having problems with dependencies we recommend installing Mantid into a new clean environment with no other packages. Please do not specify any dependency versions e.g. Python. All dependencies will be installed automatically with the version required to use Mantid. Problems with resolving dependencies is often caused by installing other packages into the same environment that require different versions of the same dependency. You can view the direct dependencies of recent stable versions of mantid available through conda-forge require by running the following command

mamba search -c mantid mantid --info

To list the currrent depedencies being used in the nightly replace the channel name with mantid/label/nightly.

404 error when trying to install#

Mantid’s dependencies are all available through conda-forge. To access this channel please check your .condarc file. It should contain the following

channels:
        - conda-forge

or

channels: [conda-forge]

If either of these are in the file then please make sure there are no other channels added for accessing Mantid. For example any of the following will cause a 404 error and should be removed from .condarc

channels:
        - https://anaconda.org/mantid
        - mantid

Qt platform plugin error#

On Windows, if you are met with the following error upon launching workbench

qt.qpa.plugin: Could not find the Qt platform plugin "windows" in ""
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Deactivate your environment, reactivate it, and run workbench again.

Still having problems?#

If the above has not resolved your problem please post to our community forum or e-mail the team directly on mantid-help@mantidproject.org.