I have this:

❯ cat .envrc
export DOCKER_HOST_IP="${${DOCKER_HOST#tcp://}%:[0-9]*}"

direnv doesn't like this.

❯ cd smdevstack
direnv: loading .envrc
./.envrc: line 2: ${${DOCKER_HOST#tcp://}%:[0-9]*}: bad substitution

❯ echo $DOCKER_HOST_IP

but it works when I manually source the file from my shell (zsh):

❯ source .envrc

❯ echo $DOCKER_HOST_IP
192.168.99.101

Why is that? I guess direnv is limited in the fanciness of what you can use in a .envrc?

If you're curious about the context of why I am trying to do such things in an .envrc, see docker/compose#2915 (comment)