Defaults and conda-forge incompatibilities

This issue is created to remind that conda-forge and defaults have incompatibilities. To fix this, there are two ways.

1. `conda-forge` channel must have higher priority than `defaults` channel. To check, run `conda config --get channels` which gives you the channel priority order. `conda config --add channels conda-forge` would make `conda-forge` the highest priority channel.

2. When creating conda-forge packages, make sure the dependencies come from conda-forge. (There are few like `libgcc` that `conda-forge` is relying on defaults). If there's a dependency missing in conda-forge, add them as well because this missing dependency pulled in from defaults might be relying on the behaviour of another package in defaults which would conflict with conda-forge.