Mounting a single partition dd image in macOS? Using testdisk, I have made what is apparently a dd image of a single HFS+ partition (what was originially /dev/disk1s2, I think).

Now I try to mount this image file, but seemingly I cannot - even if file recognizes it as a HFS partition:

me@my-iMac:~$ hdiutil attach -imagekey diskimage-class=CRawDiskImage -nomount /Volumes/Test/image.dd 
/dev/disk2                                              

me@my-iMac:~$ hdiutil mount /dev/disk2 
hdiutil: mount failed - no mountable file systems

me@my-iMac:~$ hdiutil imageinfo /Volumes/Test/image.dd 
hdiutil: imageinfo failed - image not recognized

me@my-iMac:~$ file /Volumes/Test/image.dd 
/Volumes/Test/image.dd: Macintosh HFS Extended version 4 data (mounted) last mounted by: 'HFSJ', created: Wed Jul  4 14:32:40 2018, last modified: Thu Jul 19 09:07:22 2018, last checked: Wed Jul  4 10:32:40 2018, block size: 8192, number of blocks: 366241334, free blocks: 365063585


Is it possible to somehow mount this partition image in macOS/OSX as read/write?
This doesn't answer the exact question, but the following has worked for me to mount a dd msdos image as read-only (-o ro).
$ hdiutil attach -nomount /Users/sunknudsen/Desktop/boot-clean.img
/dev/disk2

$ mkdir -p ~/Desktop/boot-clean
$ mount -o ro -t msdos /dev/disk2 ~/Desktop/boot-clean