installing fermipy

[NithyaSathyan]

Hii..
I am trying to install fermipy using the following
conda create --name fermipy -c conda-forge -c fermi python=3.9 "fermitools>=2.2.0" healpy gammapy
conda activate fermipy
pip install fermipy
but i get the following error
conda create --name fermipy -c conda-forge -c fermi python=3.9 "fermitools>=2.2.0" healpy gammapy
2 channel Terms of Service accepted
Channels:

• conda-forge
• fermi
• defaults
  Platform: linux-64
  Collecting package metadata (repodata.json): done
  Solving environment: failed

LibMambaUnsatisfiableError: Encountered problems while solving:

• unsupported request
• unsupported request
• nothing provides cppunit needed by fermitools-2.2.0-py39h93a0a19_0

Could not solve for environment specs
The following packages are incompatible
├─ fermitools >=2.2.0 * is not installable because it requires
│ └─ cppunit =* , which does not exist (perhaps a missing channel);
├─ gammapy = * does not exist (perhaps a typo or a missing channel);
└─ healpy =* * does not exist (perhaps a typo or a missing channel).

Please help me with this. My operating system is Ubuntu 18.04.2

[HealthyPear]

If it can help you, I usually write a conda environment file (better for reproducibility) with at least these contents,

name: fermipy-1.4.0
channels:
  - conda-forge
dependencies:
  - fermipy=1.4.0
  - fermi::fermitools=2.4.0