This is easily reproduced on a standalone Cent 6 or Cent 7 machine.

Create a job:

• Uses Git
• A trivial build step that fails, "false" or "exit 1" in the shell build-step for example
• Uses one of the above retry mechanisms (Naginator or Rebuilder)
• In the case of Naginator, stub it with a regex to keep it from automatically retrying
• In the case of Rebuilder, enable the rebuild without parameters
• Make a commit and run a build. It should fail. Note Git SHA (This is build #1)
• Make a second commit, then build it. It should also fail. Note the Git SHA (This is build #2)
• Now go back to build #1 and retrigger it. (build #3)

Expectation:

The retriggered build (build #3) should use the same Git SHA as build #1.

Observed problem:

The Git SHA is the HEAD of the branch at the time of the retrigger.