Enhancement: ability to vendor multiple environment.yaml files into a single local-channel

[rigzba21]

I ran into a situation where I needed to create two separate conda environments, each with different versions of the same package but solvable from a single conda-vendor'ed local channel.

Example:
environment-1.yaml:

name: environment-one
channels:
  - conda-forge
dependencies:
  - python=3.9.7
  - pip
  - gxx_linux-64=9.4.0

environment-2.yaml:

name: environment-two
channels:
  - conda-forge
dependencies:
  - python=3.9.7
  - pip
  - gxx_linux-64=11.2.0

My current workaround involved creating two separate conda-vendor'ed local-channels for each environment.yaml, then manually combining the .tar.bz2 packages into one local-channel, deleting the repodata.json files, re-indexing that channel with conda index ., and then manually merging the meta-manifest files into one (removing any duplicate entries).

It would be awesome to have the ability to create a single local channel from multiple environment.yaml files without the workaround!

[rigzba21]

Experiencing the same or similar issue when trying to generate a local channel with both nb_conda_kernels and ipykernel.

[tylerpotts]

@rigzba21 This issue is most likely happening because you are using conda index which will overwrite any of the changes that occurred when the repodata was hotfixed

The solution is to combine the meta-manifest.yaml files and the creating the local conda channels from that combined manifest. I'll add an option in the CLI that will combine meta-manifests