The 'pid' order was added, but the equivalent comparator was not back in
8b800d3af2d8c ("Add the PID column to the list of sort keys.").
`ordernames` indices need to match `compares` indices in order for this
to work.
A future commit will restructure all of this to make it less error prone
going forward (see D37083).
MFC after: 3 days
Reviewed by: pstef (D37083)
deb63adf94