DFX sometimes omits a canister in `.env`

I tried the following:

1. `git clone https://github.com/vporton/icp-package-manager`
2. `git checkout f5e961e`
3. `dfx deploy RepositoryIndex`

I expected to see this happen: `.env` file to be created.

Instead, this happened: `.env` file was not created.

### Meta

`dfx --version`:
```
dfx 0.20.1
```