# Flox isn't setting environment variables in project environments
**URL:** https://discourse.flox.dev/t/flox-isnt-setting-environment-variables-in-project-environments/720
**Category:** Help
**Tags:** closed, abandoned
**Created:** [April 10, 2023, 7:58pm UTC](https://discourse.flox.dev/t/flox-isnt-setting-environment-variables-in-project-environments/720 "2023-04-10T19:58:34Z")
**Posts on this page:** 13
**Page:** 1
### Author:  [@superbird](https://discourse.flox.dev/u/superbird)
#### Post date: [April 10, 2023, 7:58pm UTC](https://discourse.flox.dev/t/flox-isnt-setting-environment-variables-in-project-environments/720/1 "2023-04-10T19:58:34Z")
Flox doesn’t set environment variables I declare in a project-level `flox.nix`. Here’s my customized `flox.nix` after running `flox init --template project`:
```plaintext
# Set environment variables
environmentVariables.LANG = "en_US.UTF-8";
environmentVariables.PYTHONPATH = "$PYTHONPATH:$PWD/ __pypackages__ /3.11/lib";
environmentVariables.PATH = "$PATH:$PWD/ __pypackages__ /3.11/lib";
packages.nixpkgs-flox.python311 = { };
}
```
And outputs of commands that should give an idea of the problem.
```sh
❯ flox init --template project
Found git repo: /home/taohansen/Downloads/projects/mothers_emblems
wrote: /home/taohansen/Downloads/projects/mothers_emblems/flake.nix
wrote: /home/taohansen/Downloads/projects/mothers_emblems/flox.nix
Run 'flox activate' to enter the environment.
mothers_emblems on main [✘!+?] is 📦 v0.1.0 via 🐍 v3.10.10 took 8s
❯ flox install python311
Installed 'python311' package(s) into '.#default' environment.
mothers_emblems on main [✘!+?] is 📦 v0.1.0 via 🐍 v3.10.10 took 4s
❯ flox activate
mothers_emblems on main [✘!+?] is 📦 v0.1.0 via 🐍 v3.11.2
❯ exit
exit
mothers_emblems on main [✘!+?] is 📦 v0.1.0 via 🐍 v3.10.10 took 15s
❯ flox activate
mothers_emblems on main [✘!+?] is 📦 v0.1.0 via 🐍 v3.11.2
echo $LANG
en_DK.UTF-8
mothers_emblems on main [✘!+?] is 📦 v0.1.0 via 🐍 v3.11.2 took 3s
❯ exit
exit
mothers_emblems on main [✘!+?] is 📦 v0.1.0 via 🐍 v3.10.10 took 1m22s
❯ flox activate
mothers_emblems on main [✘!+?] is 📦 v0.1.0 via 🐍 v3.11.2
❯ echo $PATH
/home/taohansen/Downloads/projects/mothers_emblems/.flox/envs/x86_64-linux.default/bin:/home/taohansen/.local/share/flox/environments/worldofgeese/x86_64-linux.default/bin:/home/taohansen/.nix-profile/bin:/nix/var/nix/profiles/default/bin:/home/taohansen/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/bin:/var/lib/flatpak/exports/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl:/var/lib/snapd/snap/bin:/home/taohansen/bin:/home/taohansen/.garden/bin
mothers_emblems on main [✘!+?] is 📦 v0.1.0 via 🐍 v3.11.2 took 7s
❯ echo $PYTHONPATH
```
It’s odd because I’m just coming back to Flox after a few weeks where I may have hallucinated this all working 🤷
I’m running v0.1.3.
---
### Author:  [@aameen](https://discourse.flox.dev/u/aameen)
#### Post date: [April 11, 2023, 2:26pm UTC](https://discourse.flox.dev/t/flox-isnt-setting-environment-variables-in-project-environments/720/2 "2023-04-11T14:26:32Z")
Hey thanks for the report, I’ll see if I can help debug a bit.
You’re right that with the `flox.nix` file you’ve written `LANG` should be set to `en_US.UTF-8` inside the environment.
I’ll start by trying to reproduce the issue, so getting a bit more info about your shell and “rc script” would help me investigate.
My immediate suspicion is that a profile script such as `~/.bashrc` or `~/.zshrc` is likely setting `LANG` after `flox activate` runs its profile setup. If you could share any relevant snippets from any `~/.profile` or “rc scripts” related to `LANG` settings that would be a big help.
---
### Author:  [@superbird](https://discourse.flox.dev/u/superbird)
#### Post date: [April 12, 2023, 6:54pm UTC](https://discourse.flox.dev/t/flox-isnt-setting-environment-variables-in-project-environments/720/3 "2023-04-12T18:54:40Z")
Thanks! It’s not just `LANG`, `PYTHONPATH` returns empty when it should be returning `$PYTHONPATH:$PWD/ __pypackages__ /3.11/lib`. Neither my `.bashrc` or `.profile` are setting any of these values.
My `home.nix` is at [home.nix · GitHub](https://gist.github.com/worldofgeese/6460b8332a834538259e3f861c940578)
---
### Author:  [@aameen](https://discourse.flox.dev/u/aameen)
#### Post date: [April 12, 2023, 7:47pm UTC](https://discourse.flox.dev/t/flox-isnt-setting-environment-variables-in-project-environments/720/4 "2023-04-12T19:47:22Z")
One thing I caught was that you were trying to use `$PWD` when declaring a shell variable.
One important behavior to take note of is that these variables are set “literally”, so no shell expansion is performed.
Here’s an example:
```auto
$ mkdir /tmp/example;
$ cd /tmp/example;
$ flox init -t project -i;
$ cat <<'EOF' > ./flox.nix;
{
environmentVariables.LANG = "en_US.UTF-8";
environmentVariables.GOOD = toString ./.;
environmentVariables.BAD = "$PWD";
shell.hook = ''
echo "LANG: $LANG" >&2;
echo "GOOD: $GOOD" >&2;
echo "BAD: $BAD" >&2;
'';
}
EOF
# re-render environment since we manually modified it:
$ EDITOR=cat flox edit -e '.#default';
# To prove that LANG gets set we'll use a junk value in another shell:
$ bash -c "export LANG=xxxx; . <( flox activate -e '.#default'; );";
LANG: en_US.UTF-8
GOOD: /tmp/example
BAD: $PWD
```
Are you by any chance using `direnv`?
There might be additional hooks being executed there.
---
### Author:  [@superbird](https://discourse.flox.dev/u/superbird)
#### Post date: [April 13, 2023, 5:59pm UTC](https://discourse.flox.dev/t/flox-isnt-setting-environment-variables-in-project-environments/720/5 "2023-04-13T17:59:20Z")
How should one be doing shell expansion with Flox?
I usually use `direnv` but for this example I’ve purged any `.envrc`
---
### Author:  [@aameen](https://discourse.flox.dev/u/aameen)
#### Post date: [April 13, 2023, 6:00pm UTC](https://discourse.flox.dev/t/flox-isnt-setting-environment-variables-in-project-environments/720/6 "2023-04-13T18:00:30Z")
Shell expansion will work in the `shell.hook`.
So this works:
```auto
{
environmentVariables.FOODIR = "foo";
shell.hook = ''
FOO="$PWD/$FOODIR";
'';
}
```
---
### Author:  [@superbird](https://discourse.flox.dev/u/superbird)
#### Post date: [April 13, 2023, 6:21pm UTC](https://discourse.flox.dev/t/flox-isnt-setting-environment-variables-in-project-environments/720/8 "2023-04-13T18:21:57Z")
I tried this
````plaintext
{
# Run shell hook when you enter flox environment
shell.hook = ''
PYTHONPATH="$PYTHONPATH:$PWD/ __pypackages__ /3.11/lib";
PATH="$PATH:$PWD/ __pypackages__ /3.11/bin";
'';
packages.nixpkgs-flox.python311 = { };
}
```sh
then activated my Flox environment
mothers_emblems on main [✘!+?] is 📦 v0.1.0 via 🐍 v3.10.10
❯ flox activate
````
which returned an empty `PYTHONPATH`
```sh
mothers_emblems on main [✘!+?] is 📦 v0.1.0 via 🐍 v3.11.2
❯ echo $PYTHONPATH
```
---
### Author:  [@aameen](https://discourse.flox.dev/u/aameen)
#### Post date: [April 13, 2023, 6:44pm UTC](https://discourse.flox.dev/t/flox-isnt-setting-environment-variables-in-project-environments/720/9 "2023-04-13T18:44:06Z")
Out of curiosity did you manually edit `flox.nix` or did you use `flox edit`?
There’s an unintuitive behavior ( we are working on it ) where you have to run `flox edit` to “refresh” a modified `flox.nix` file.
If you prefer to use a regular text editor you can run `EDITOR=true flox edit ;` for the time being until we can roll out an improvement.
If you did use `flox edit` already, let me know and we can get into some more debugging.
I appreciate the report and your patience with this 🙂
---
### Author:  [@superbird](https://discourse.flox.dev/u/superbird)
#### Post date: [April 13, 2023, 6:48pm UTC](https://discourse.flox.dev/t/flox-isnt-setting-environment-variables-in-project-environments/720/10 "2023-04-13T18:48:51Z")
I appreciate _your_ patience with _me_! You didn’t have to help but you did 🤗
I did not use `flox edit` but it looks like that’s gone some way to helping! `PATH` and `PYTHONPATH` are still not performing expansions but they are being populated
```sh
mothers_emblems on main [✘!+?] is 📦 v0.1.0 via 🐍 v3.11.2
❯ echo $PYTHONPATH
:/home/taohansen/Downloads/projects/mothers_emblems/ __pypackages__ /3.11/lib
```
---
### Author:  [@superbird](https://discourse.flox.dev/u/superbird)
#### Post date: [April 14, 2023, 5:35pm UTC](https://discourse.flox.dev/t/flox-isnt-setting-environment-variables-in-project-environments/720/12 "2023-04-14T17:35:31Z")
@aameen 👋 I saw you wrote a reply yesterday but it evaporated as quickly as it appeared. Was that a mistake or was there more research necessary? Happy to try any changes.
---
### Author:  [@aameen](https://discourse.flox.dev/u/aameen)
#### Post date: [April 14, 2023, 5:59pm UTC](https://discourse.flox.dev/t/flox-isnt-setting-environment-variables-in-project-environments/720/13 "2023-04-14T17:59:07Z")
I had written a recommendation about escaping `${FOO}` style variable expansion in your `flox.nix` file, but after re-reading your post I realized that wasn’t the issue.
I think I know why `PYTHONPATH` is not populating and need to cook up a nice explanation and example to teach you how to fix it. Just to help confirm my suspicion, in your source tree do you currently have a `/__pypackages_/3.11/lib` directory containing modules?
Also could you confirm that `PATH` was fixed by my previous recommendation?
---
### Author:  [@superbird](https://discourse.flox.dev/u/superbird)
#### Post date: [April 14, 2023, 7:16pm UTC](https://discourse.flox.dev/t/flox-isnt-setting-environment-variables-in-project-environments/720/14 "2023-04-14T19:16:35Z")
> [@aameen](#):
>
> in your source tree do you currently have a `/__pypackages_/3.11/lib` directory containing modules?
I do!
```sh
✦ ❯ exa --tree --level=2 __pypackages__
__pypackages__
└── 3.11
├── bin
├── etc
├── include
├── lib
├── LICENSE.txt
├── README.rst
├── requirements.txt
└── share
```
> [@aameen](#):
>
> Also could you confirm that `PATH` was fixed by my previous recommendation?
It appears so
```sh
❯ echo $PATH
/home/taohansen/Downloads/projects/mothers_emblems/.flox/envs/x86_64-linux.default/bin:/home/taohansen/.local/share/flox/environments/worldofgeese/x86_64-linux.default/bin:/home/taohansen/.nix-profile/bin:/nix/var/nix/profiles/default/bin:/home/taohansen/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/bin:/var/lib/flatpak/exports/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl:/var/lib/snapd/snap/bin:/home/taohansen/bin:/home/taohansen/.garden/bin:/home/taohansen/Downloads/projects/mothers_emblems/ __pypackages__ /3.11/bin
```
---
### Author:  [@aameen](https://discourse.flox.dev/u/aameen)
#### Post date: [April 18, 2023, 4:07pm UTC](https://discourse.flox.dev/t/flox-isnt-setting-environment-variables-in-project-environments/720/15 "2023-04-18T16:07:00Z")
One thing you can try changing in your setup hook is to only add “:” if `PYTHONPATH` is already set.
Right now you’re getting `:/ __pypackages__ /3.11/lib` which may cause issues.
You can use the following. Just to help debug I’ll add a few extra prints:
```plaintext
{
environmentVariables.LANG = "en_US.UTF-8";
packages.nixpkgs-flox.python311 = {};
shell.hook = ''
PYTHONPATH="$PWD/ __pypackages__ 3.11/lib''${PYTHONPATH:+:$PYTHONPATH}";
export PYTHONPATH;
echo "PWD: $PWD" >&2;
echo "LANG: $LANG" >&2;
ls -R >&2;
'';
}
```