JDK-8197943 : Unable to use JDWP API in JDK 8 to debug JDK 9 VM
  • Type: Bug
  • Component: core-svc
  • Sub-Component: debugger
  • Affected Version: 8
  • Priority: P3
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2018-02-14
  • Updated: 2019-01-14
  • Resolved: 2018-03-06
The Version table provides details related to the release that this issue/RFE will be addressed.

Unresolved : Release in which this issue/RFE will be addressed.
Resolved: Release in which this issue/RFE has been resolved.
Fixed : Release in which this issue/RFE has been fixed. The release containing this fix may be available for download as an Early Access Release or a General Availability Release.

To download the current JDK release, click here.
JDK 8 Other
8u181Fixed openjdk7uFixed
Sub Tasks
JDK-8203242 :  
Release Note: Unable to use the JDWP API in JDK 8 to debug JDK >=9 - Closed
Description
Reported @ http://mail.openjdk.java.net/pipermail/serviceability-dev/2018-February/022934.html

there's a bug in VirtualMachineImpl.canGetInstanceInfo:
if (versionInfo().jdwpMajor < 1 ||
     versionInfo().jdwpMinor < 6) {
     return false;
} 
it returns false because jdwpMinor is 0 for jdk 9
Comments
I will backport.
16-02-2018
JDWP is part of JPDA (Java Platform Debugger Architecture). Moving this bug from core-svc/tools -> core-svc/debugger.
15-02-2018
Note, this issue only exist in 8 and earlier. 9 and later don't have this issue. Basically you can't used JDWP from and 8 or earlier VM to debug a 9 or later VM. The issue is that with 9 the version number changed from 1.8 to 9.0, so that is confusing some version checking compatibility checks that jdwp does. It expects minor to be 6 or later when checking for features introduced in 1.6.
14-02-2018