I wrote:
> Sadly, it seems adder[1] is even pickier than mamba:
Nope, it was my testing error: I supposed that this patch only
affected pg_combinebackup and pg_verifybackup, so I only
recompiled those modules not the whole tree. But there's one
more place with a json_manifest_per_file_callback callback :-(.
I pushed a quick-hack fix.
regards, tom lane