Issue with babel watch

| Title | Description
| --------------------|------------
| Version | 0.22.6
| Type | Issue
| node | v11.9
| Operating System | macOS Mojave (10.14.3)
| Short Description | Execution limited to 12 items when using the watch flag on babel

**Detailed description**

Everytime I run the following command, bolt is only processing 12 packages (instead of all the 22 packages). When I remove the `watch` flag on babel (`-w`) everything works just fine.

```node
bolt ws exec --parallel -- babel src -w -d dist/esm --root-mode upward"
```

Thank you for your insight.

No files or tests are identified. Start by reproducing the command in a workspace containing 22 packages, comparing `bolt ws exec --parallel` with and without Babel's `-w` flag on the stated versions. Done means identifying why watch mode processes only 12 packages and verifying that all packages are processed.

Written by the indexing model from the issue text.