pbulk rebuilds everything

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

Hello,
I updated my pkgsrc tree (from 2022Q4 to HEAD) and ran a partial pbulk,
which completed.
Now every time I redo a pbulk, it rebuilds all packages (which takes a while).
Any idea what could cause this, or how to find what causes this ?
The first time I though it was because I edited my mk.conf
(adding a setting which affects only one package), but this time I only
updated changed kicad ans ng-spice.
I didn't have this issue with 2022Q4 and didn't change by pbulk
setup.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--