TLDR

I have a use case for nesting directories with cascading .envrc files. and ran into an issue where the parent environment was being reset by the child environment. The fix is source_up

Context

I manage some infrastructure at home with a folder like this:

        
.
├── homelab
│   ├── .envrc
│   └── stack1
│       ├── .envrc

I do this so that the "homelab-wide" terraform variables can be exported with TF_VAR_the_variable in the homelab/.envrc and then the stack specific variables in stack1/.envrc get exported like TF_VAR_stack_specific_var.

For example, my cloudflare account id is needed in every stack, but the cloudflare zone id is different per stack - so instead of copying the account id var to every stack (however the vars are managed), I can set it in a parent .envrc and share it in nested stack directories

Problem

        
# homelab/.envrc
#!/bin/bash
export VAR_FOO=BAR

So when I cd homelab I get

        
nic in /tmp/homelab   (dev) 󰒄 󱔎 NO PYTHON ENVIORNMENT SET
⬢ [devbox] ❯ direnv allow
direnv: loading /tmp/homelab/.envrc
direnv: export +VAR_FOO

nic in /tmp/homelab   (dev) 󰒄 󱔎 NO PYTHON ENVIORNMENT SET
⬢ [devbox] ❯ env | grep VAR
VAR_FOO=BAR

You can see VAR_FOO is set... but now I'll cd stack1

        
nic in /tmp/homelab   (dev) 󰒄 󱔎 NO PYTHON ENVIORNMENT SET
⬢ [devbox] ❯ cd stack1
direnv: error /tmp/homelab/stack1/.envrc is blocked. Run `direnv allow` to approve its content

nic in /tmp/homelab/stack1   (dev) 󰒄 󱔎 NO PYTHON ENVIORNMENT SET
⬢ [devbox] ❯ direnv allow
direnv: loading /tmp/homelab/stack1/.envrc
direnv: export +VAR_BAZ

nic in /tmp/homelab/stack1   (dev) 󰒄 󱔎 NO PYTHON ENVIORNMENT SET
⬢ [devbox] ❯ env | grep VAR
VAR_BAZ=BAM

As you can see VAR_FOO was unset, and VAR_BAZ is set... so homelab/.envrc was blown away!

Fix

Edit stack1/.envrc with a source_up command

        
# stack1/.envrc # NEW
#!/bin/bash
source_up  # source the parent environment
export VAR_BAZ=BAM

After the edit

        
nic in /tmp/homelab/stack1   (dev) 󰒄 󱔎 NO PYTHON ENVIORNMENT SET
⬢ [devbox] ❯ vim .envrc
direnv: error /tmp/homelab/stack1/.envrc is blocked. Run `direnv allow` to approve its content

nic in /tmp/homelab/stack1   (dev) 󰒄 󱔎 NO PYTHON ENVIORNMENT SET  took 5s
⬢ [devbox] ❯ direnv allow
direnv: loading /tmp/homelab/stack1/.envrc
direnv: loading /tmp/homelab/.envrc
direnv: export +VAR_BAZ +VAR_FOO

nic in /tmp/homelab/stack1   (dev) 󰒄 󱔎 NO PYTHON ENVIORNMENT SET
⬢ [devbox] ❯ env | grep VAR
VAR_FOO=BAR
VAR_BAZ=BAM

Both vars are set!