Jtreg tests fail without producing any error message (from the JSON parser) if there is an error in the CompilerDirectivesFile. This can be demonstrated by using "-XX:CompilerDirectivesFile=/dev/null".

Using "make run-test" with a jtreg test will result in:

Running tests using TEST_OPTS control variable 'VM_OPTIONS=-XX:CompilerDirectivesFile=/dev/null'
Test selection 'jdk/incubator/vector/Short64VectorTests.java', will run:
* jtreg:open/test/jdk/jdk/incubator/vector/Short64VectorTests.java

Running test 'jtreg:open/test/jdk/jdk/incubator/vector/Short64VectorTests.java'
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.


A similar run with a gtest will show the error from the JSON parser:

Running tests using TEST_OPTS control variable 'VM_OPTIONS=-XX:CompilerDirectivesFile=/dev/null'
Test selection 'gtest:codestrings', will run:
* gtest:codestrings/server

Running test 'gtest:codestrings/server'
Note: Google Test filter = codestrings*
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from codestrings
[ RUN ] codestrings.validate_vm
Syntax error on line 1 byte 1: EOS was encountered before any json declarations
  Got EOS.

Parsing of compiler directives failed
Could not load file: /dev/null