trouble installing isce2 in Colab: "cudatoolkit=12.2 is missing from the target environment"

Question

I run the fallowing instructions, but it dosen't work!

!nvcc --version
**nvcc: NVIDIA (R) Cuda compiler driver
Copyright (c) 2005-2023 NVIDIA Corporation
Built on Tue_Aug_15_22:02:13_PDT_2023
Cuda compilation tools, release 12.2, V12.2.140
Build cuda_12.2.r12.2/compiler.33191640_0**

!conda install -c conda-forge isce2
**Collecting package metadata (current_repodata.json): done
Solving environment: failed with initial frozen solve. Retrying with flexible solve.
Solving environment: failed with repodata from current_repodata.json, will retry with next repodata source.
Collecting package metadata (repodata.json): done
Solving environment: failed with initial frozen solve. Retrying with flexible solve.

PackagesNotFoundError: The following packages are missing from the target environment:
  - cudatoolkit=12.2**

I tried installing with conda install -c "conda-forge/label/cf202003" isce2 but it didn't work either.

Answer 1

Conda Forge not yet building cudatoolkit=12.2

This is reported in this condacolab Issue. Essentially, the presence of CUDA v12.2 triggers Conda (or condacolab?) to inject a pin of cudatoolkit 12.2.*, but Conda Forge isn't yet building cudatoolkit=12.2. This renders any mutating operation with Conda/Mamba broken for now. Eventually, this will be fixed (follow the Issue).

Workaround

In the meantime, one can simply remove the pinning with:

!sed -i '/cudatoolkit/d' /usr/local/conda-meta/pinned

and then Conda should function normally.

Here's a demo notebook where I install isce2 and check the version after loading in Python.