[conda] Caching a conda installation

[Michael Milton]

I'm using conda (miniconda) packages as part of my CI build, so to speed
things up I want to cache the entire conda environment so that it doesn't
have to install every time. To this end, I save /opt/conda (which is where
conda is installed in the continuumio/miniconda Docker image
<https://hub.docker.com/r/continuumio/miniconda/>) to a cache location, and
restore this cache at the start of each build.

However, if I restore that cache in a build and then run the `conda
install` command again, I get two issues:

- It doesn't seem to detect that all these packages are already
installed, and I get "The following NEW packages will be INSTALLED"
message, followed by an attempted installation.
- When conda tries to actually install these packages, I get hundreds of
errors saying things like:

CondaVerificationError: The package for openssl located at
/opt/conda/pkgs/openssl-1.0.2p-h14c3975_0
appears to be corrupted. The path 'ssl/man/man3/ASN1_OBJECT_free.3'
specified in the package manifest cannot be found.

CondaVerificationError: The package for openssl located at
/opt/conda/pkgs/openssl-1.0.2p-h14c3975_0
appears to be corrupted. The path 'ssl/man/man3/ASN1_STRING_print_ex.3'
specified in the package manifest cannot be found.


Why is this happening? How should I be caching a conda environment (without
having to re-install all of these packages each time)? Am I missing another
folder that I should also be caching?

Thanks.

[Michael Milton]

I don't know if I can check for sure, but this is in AWS CodeBuild so I
doubt they would use an unconventional filesystem.

[Michael Milton]

Alternatively, since this doesn't seem to work, is there a package cache of
tarballs I could cache instead? Equivalent to Pip's ~/.cache/pip.