v4.2.2

Changelog

• 82c6a19 fix: bound every package-manager probe so a hung manager cannot wedge genv (#111)
• df014a1 fix: fsync spec and lock files before publishing the rename (#113)
• d79e2a6 fix: updates worker waits for in-flight upgrades and notifications before exiting (#116)
• 8b56d21 fix: write pulled spec via temp+rename so an interrupted pull cannot truncate it (#114)