parquet-tools merge does not work nor give any error message

When I run

```Java

java -jar ./parquet-mr/parquet-tools/target/parquet-tools-1.9.1-SNAPSHOT.jar merge $inpath $outpath
```

It does not work, no matter what combination of $inpath or $outpath I use.

It gives exit code 1, but never produces an error message or any indication of what is wrong.

**Reporter**: [sam](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=sams) / @samthebest

_{**Note**: *This issue was originally created as [PARQUET-1132](https://issues.apache.org/jira/browse/PARQUET-1132). Please see the [migration documentation](https://issues.apache.org/jira/browse/PARQUET-2502) for further details.*}

Start with the parquet-tools merge command shown in the issue and inspect the parquet-mr/parquet-tools module. Run the reported java -jar invocation with representative input and output paths, then trace why it exits with code 1 without reporting an error. Done means merge failures provide a useful error message or indication of what went wrong.

Written by the indexing model from the issue text.