# `package.not_installed`

Lock names a package that isn't installed.

Area 11, [External services](../topics/external-services.md); not declinable; the next step is usually the human's.

Each line of the lock is a package in `packages/`:


```jadpo
// Generated by Jadpo from the installed packages; update it with `jadpo package add`, `update` or `remove`, never by hand.
record lock 1

package Postcodes.v2 version 2.1.0 path ../postcodes digest sha256:0000000000000000000000000000000000000000000000000000000000000000
```

```text
error: `jadpo.lock` names `Postcodes.v2`, which isn't installed
 --> jadpo.lock
  reason: Each line of the lock is a package in `packages/`; `Postcodes.v2` has none at `packages/postcodes/v2/`, so the lock and the folder disagree, as removing the folder by hand leaves them.
  next: Restore `packages/postcodes/v2/` from version control, or remove the package with `jadpo package remove` (human)
  rule: package.not_installed
  help: https://jadpo.dev/docs/errors/package.not_installed

check failed: 1 error, 1 file
```