What steps will reproduce the problem?
1. Write a test with a failing ASSERTion, especially in a helper function.
2. Run the test.

What is the expected result?
  Be able to easily understand the cause of the failure. A stack trace would be helpful.

What happens instead of that?
  No stack trace, which leads to hard-to-understand failures when the assertion is in a helper function.

Developers will sometimes fall back to (D)CHECKs to get stack traces instead.