Uninformative error message from qltest when there are no source files

I ran odasa qltest on a test directory in which I'd neglected to include any source files.

Expected: The extractor should fail with a message like "There are no source files in this test directory."

Actual: The extractor fails with a null pointer exception.

[1/3] Extraction failed in D:\dev\codeql-2\msft\cpp\ql\test\query-tests\Maintainability\CopyrightNoticeCommentsExpertise (extraction: 175ms)
java.lang.NullPointerException
java.nio.file.Files.provider(Files.java:97)
java.nio.file.Files.exists(Files.java:2385)
com.semmle.api.QueryEngine.createDatabase(QueryEngine.java:486)
com.semmle.odasa.qltest.TestDirectory.createDatabase(TestDirectory.java:483)
com.semmle.odasa.qltest.TestDirectory.importTrap(TestDirectory.java:583)
com.semmle.odasa.qltest.TestDirectory.extract(TestDirectory.java:310)
com.semmle.odasa.actions.Qltest.lambda$executeTests$0(Qltest.java:230)
java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
java.util.concurrent.FutureTask.run(FutureTask.java:266)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
java.lang.Thread.run(Thread.java:748)

Let me know if this isn't the right repo to file this in.

[jketema]

Apologies for this issue going unnoticed. odasa is no longer supported. Closing this issue.