cabal v2-repl --ghcjs doesn't open a repl nor show an error message

**Describe the bug**
Cabal doesn't open a repl using `--ghcjs` and is not showing any error or warning

**To Reproduce**
Steps to reproduce the behavior:

```
D:\dir> cabal get HsYAML-0.2.1.0
D:\dir> cd HsYAML-0.2.1.0
D:\dir\HsYAML-0.2.1.0> cabal v2-repl --ghcjs
Warning: don't know how to find change monitoring files for the installed
package databases for ghcjs
Resolving dependencies...
Build profile: -w ghcjs-8.6.0.1 -O1
In order, the following will be built (use -v for more details):
- HsYAML-0.2.1.0 (lib) (file src\Data\YAML.hs changed)
Preprocessing library for HsYAML-0.2.1.0..
```

**Expected behavior**
Cabal should open a repl or at least exit with an informative error.

**System information**
- Windows 7 and 10
- `cabal-3.0.0.0`,
- `ghcjs-8.6.0.1-8.6.5` built from source

Reproduce the Windows command sequence with cabal-3.0.0.0 and ghcjs-8.6.0.1, then trace how `cabal v2-repl --ghcjs` handles the build after preprocessing. Done means the command opens a REPL or exits with an informative error or warning instead of stopping silently.

Written by the indexing model from the issue text.