try incremental=no

Author: src-up

mkosi.conf.d/fedora/mkosi.conf.d/arm64-uki-signed.conf

@@ -9,7 +9,5 @@ Bootloader=uki-signed
 # Bootloader=uki-signed. Not available on all Fedora architectures (e.g. ppc64le),
 # so kept in arch-specific configs and gated on Bootloader=uki-signed. A separate
 # file is needed to match both Architecture= and Bootloader= simultaneously.
-# VolatilePackages= is used so this package does not appear in the cache manifest,
-# allowing --incremental=strict to reuse the cached image.
-VolatilePackages=
+Packages=
         kernel-uki-virt

mkosi.conf.d/fedora/mkosi.conf.d/x86_64-uki-signed.conf

@@ -9,7 +9,5 @@ Bootloader=uki-signed
 # Bootloader=uki-signed. Not available on all Fedora architectures (e.g. ppc64le),
 # so kept in arch-specific configs and gated on Bootloader=uki-signed. A separate
 # file is needed to match both Architecture= and Bootloader= simultaneously.
-# VolatilePackages= is used so this package does not appear in the cache manifest,
-# allowing --incremental=strict to reuse the cached image.
-VolatilePackages=
+Packages=
         kernel-uki-virt

tests/test_boot.py

@@ -80,5 +80,12 @@ def test_bootloader(config: ImageConfig, bootloader: Bootloader) -> None:
     firmware = Firmware.linux if bootloader == Bootloader.none else Firmware.auto
 
     with Image(config) as image:
-        image.build(["--format=disk", "--bootloader", str(bootloader)])
+        image.build(
+            [
+                "--format=disk",
+                "--bootloader",
+                str(bootloader),
+                *(["--incremental=no"] if bootloader == Bootloader.uki_signed else []),
+            ]
+        )
         image.vm(["--firmware", str(firmware)])