live-build: move snap seed validation into snap_preseed

live-build/auto/build

@@ -88,11 +88,6 @@ preinstall_snaps() {
 		snap_preseed chroot "${snap}"
 	done
 	lb chroot_resolv remove
-
-        # Do basic validation of generated snapd seed.yaml.
-        if [ -e chroot/var/lib/snapd/seed/seed.yaml ]; then
-            snap debug validate-seed chroot/var/lib/snapd/seed/seed.yaml
-        fi
 }
 
 rm -f binary.success

live-build/functions

@@ -635,6 +635,15 @@ snap_preseed() {
             touch "$CHROOT_ROOT/var/lib/snapd/seed/.snapd-explicit-install-stamp"
             ;;
     esac
+
+    
+    # Do basic validation of generated snapd seed.yaml, doing it here
+    # means we catch all the places(tm) that snaps are added but the
+    # downside is that each time a snap is added the seed must be valid,
+    # i.e. snaps with bases need to add bases first etc.
+    if [ -e chroot/var/lib/snapd/seed/seed.yaml ]; then
+        snap debug validate-seed chroot/var/lib/snapd/seed/seed.yaml
+    fi
 }
 
 snap_from_seed() {
@@ -892,4 +901,4 @@ replace_kernel () {
         install --assume-yes "${new_kernel}" 
     env DEBIAN_FRONTEND=noninteractive chroot "${mountpoint}" apt-get \
         autoremove --purge --assume-yes
-}
+}