setup_conda.sh

#!/usr/bin/env bash
###
# NB: You probably don't want this gist any more.
#     Instead, use this version from `fastsetup`:
#     https://github.com/fastai/fastsetup/blob/master/setup-conda.sh
###

set -e

cd

case "$OSTYPE" in
  darwin*)  DOWNLOAD=https://repo.anaconda.com/miniconda/Miniconda3-latest-MacOSX-x86_64.sh; RC_FILE=.bash_profile ;;
  linux*)   DOWNLOAD=https://repo.anaconda.com/miniconda/Miniconda3-latest-Linux-x86_64.sh; RC_FILE=.bashrc  ;;
  *)        echo "unknown: $OSTYPE" ;;
esac

case "$SHELL" in
  /bin/zsh*)   SHELL_NAME=zsh; RC_FILE=.zshrc ;;
  /bin/bash*)  SHELL_NAME=bash ;;
  /usr/local/bin/fish*) SHELL_NAME=fish ;;
  *)        echo "unknown: $SHELL" ;;
esac

cat << EOF > .condarc
channels:
  - fastai
  - pytorch
  - defaults
channel_priority: strict
EOF

wget $DOWNLOAD
bash Miniconda3-latest*.sh -b
~/miniconda3/bin/conda init $SHELL_NAME
rm Miniconda3-latest*.sh

perl -n  -e 'print if     />>> conda/../<<< conda/' $RCFILE > .condainit
perl -ni -e 'print unless />>> conda/../<<< conda/' $RCFILE
echo source ~/.condainit >> $RCFILE
source ~/.condainit

I'm using fish shell (on mac) which is unfortunately not compatible with bash syntax, so instead of sourcing it, you need to start the setup with: bash setup_conda.sh. Then you will want to add the following line to the $SHELL case switch: /usr/local/bin/fish*) SHELL_NAME=fish ;; (for me fish is at /usr/local/bin/fish, check your location by running echo $SHELL). This ensures that later the conda init line will be invoked with fish as last param.

The .bashrc lines are not doing any harm on a fish system (don't have a .bashrc so .condainit will be empty and sourcing it will do nothing)

Finally I had to change the last line to conda install mamba -c conda-forge (as specified in mamba's installation guide), should not be a fish specific thing though as far as i can tell? Without specyfing conda-forge as a channel that installation failed on my machine.

And when you say "to install fastai with mamba…run" you are I think forgetting to tell users to alias conda to mamba (i know you did on twitter, but people might not have seen that coming here).

Thanks for sharing Jeremy! I had an error "setup_conda.sh: line 34: source: .condainit: file not found." My OS is Centos 7. I was able to fix the issue by switching the command to "source ~/.condainit"

Just a quick note for anyone using Ubuntu in WSL2, don't delete your ~/anaconda3 folder if you want to start fresh. Everything is broken now :(.

It seems like a great idea for managing environments. But the script seems not to be working anymore. After the miniconda install (seemingly after running the condainit script it creates), it stops, saying:
==> For changes to take effect, close and re-open your current shell. <==
Also, if I then try to run conda install -y mamba it appears not to find it in the provided channels (the current documentation recommends conda-forge?)

Leaving this here just in case: I finally added the channel manually: conda config --append channels conda-forge, after which I was able to run
conda install -y mamba

mamba is no longer needed -- I've now updated the gist to reflect that. I've also added a link to a somewhat more official version that's in fastsetup.