=== Create image with unknown header extension ===
-Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
magic 0x514649fb
version 2
backing_file_offset 0x0
refcount_order 4
header_length 72
-Header extension:
-magic 0x6803f857
-length 144
-data <binary>
-
Header extension:
magic 0x12345678
length 31
magic 0x514649fb
version 2
-backing_file_offset 0x128
+backing_file_offset 0x90
backing_file_size 0x17
cluster_bits 16
size 67108864
length 11
data 'host_device'
-Header extension:
-magic 0x6803f857
-length 144
-data <binary>
-
Header extension:
magic 0x12345678
length 31
=== Create image with unknown header extension ===
-Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
magic 0x514649fb
version 3
backing_file_offset 0x0
refcount_order 4
header_length 104
+Header extension:
+magic 0x6803f857
+length 144
+data <binary>
+
Header extension:
magic 0x12345678
length 31