Unmount the image before we convert to qcow2 to avoid corruption

live-build/ubuntu-cpc/hooks.d/base/kvm-image.binary

@@ -32,6 +32,9 @@ create_derivative "disk" "kvm" #sets ${derivative_img}
 mount_disk_image ${derivative_img} ${mount_d}
 
 # unmount disk image and remove created folders on exit
+# even though we unmount manually before we convert to
+# qcow2, we have this here just in case we error out before
+# that step
 cleanup_kvm() {
     if [ -d "$mount_d" ]; then
         umount_disk_image "$mount_d"
@@ -61,4 +64,10 @@ env DEBIAN_FRONTEND=noninteractive chroot "${mount_d}" apt-get \
     clean
 
 create_manifest ${mount_d} livecd.ubuntu-cpc.disk-kvm.manifest
+
+# unmount disk image to prevent corruption
+# and remove it so the trap doesn't try to unmount it again
+umount_disk_image ${mount_d}
+rm -rf ${mount_d}
+
 convert_to_qcow2 ${derivative_img} livecd.ubuntu-cpc.disk-kvm.img