What causes "Environment variable {key} not found" in jdx/mise?

List everything currently defined to confirm the exact key: `mise set` (no arguments)

Environment variable {key} not found

Error message

Environment variable {key} not found

What it means

`mise set KEY` with a single bare key (no =VALUE, no --prompt, no --stdin) is the read form of the command: mise resolves the merged config environment through Config::env() — which includes decrypting age-encrypted entries — and prints the value. If the key is not defined in any mise config's [env], it bails 'Environment variable {key} not found'. It reads mise config env, not the process environment.

Source

Thrown at src/cli/set.rs:155

                mise_toml.remove_env(name)?;
            }
        }

        if let Some(env_vars) = &self.env_vars
            && env_vars.len() == 1
            && env_vars[0].value.is_none()
            && !self.prompt
            && !self.stdin
        {
            let key = &env_vars[0].key;
            // Use Config's centralized env loading which handles decryption
            let full_config = Config::get().await?;
            let env = full_config.env().await?;
            match env.get(key) {
                Some(value) => {
                    miseprintln!("{value}");
                }
                None => bail!("Environment variable {key} not found"),
            }
            return Ok(());
        }

        if let Some(mut env_vars) = self.env_vars.take() {
            // Prompt for values if requested
            if self.prompt {
                let theme = crate::ui::theme::get_theme();
                for ev in &mut env_vars {
                    if ev.value.is_none() {
                        let prompt_msg = format!("Enter value for {}", ev.key);
                        let value = Input::new(&prompt_msg)
                            .password(self.age_encrypt) // Mask input if encrypting
                            .theme(&theme)
                            .run()?;
                        ev.value = Some(value);
                    }
                }

View on GitHub (pinned to 6f52dcdf99)

Solutions

List everything currently defined to confirm the exact key: `mise set` (no arguments)
Check all config layers involved: `mise config ls`, and query the specific file with `mise set --file <path> KEY`
If it should exist, define it first: `mise set FOO=bar`
If you meant the shell's environment variable, use `echo $FOO` — mise set only reads mise-managed env

Example fix

# before
mise set DATABASE_URL   # Environment variable DATABASE_URL not found

# after
mise set                  # list keys to confirm spelling
mise set --file mise.local.toml DATABASE_URL   # or query the file that defines it

Defensive patterns

Strategy: validation

Validate before calling

# confirm the key exists in mise's env before reading it
key=FOO
if mise set 2>/dev/null | awk 'NR>3 {print $1}' | grep -qx "$key"; then
  val=$(mise set "$key")
else
  echo "$key not defined in mise config env" >&2
fi

Type guard

mise_env_has() { mise set 2>/dev/null | awk '{print $1}' | grep -qx "$1"; }

Try / catch

Check `mise set KEY` exit code and stderr; 'not found' means the key is absent from mise config env — fall back to a default or fail with a clear message rather than retrying.

Prevention

Use `mise set` (no args) to inventory available keys before scripting reads
Remember this reads mise config env, not process env — use $VAR for the latter
Keep env keys in one known config layer to make lookups predictable

When it happens

Trigger: Running `mise set FOO` when FOO is not defined in any loaded mise.toml [env] table (global, project, or local), or when FOO exists only as an OS/shell environment variable rather than a mise env entry.

Common situations: Typos in the key name; expecting `mise set KEY` to read the shell environment (use `echo $KEY` instead); the variable living in a different config file or config layer than the one currently trusted/loaded.

Understand the failure class

Background: "environment variable is not set" and "Missing keys in environment" errors: what missing required env var messages mean and how to fix them — this error's family across 28 libraries.

Related errors

AI-assisted analysis of jdx/mise@6f52dcdf99 (2026-08-22). Data as JSON: /api/errors/87dd4b673e2492b2. Report an issue: GitHub.