Couldn’t mount a disk image taken from a failing HDD.

1. Attach the image file in osx:
hdiutil attach -noverify -nomount /path/to/disk.dmg

2. Download Photorec from, unpack and launch the binary file

3. Select the attached disk, confirm it’s name through terminal:
diskutil list

4. Configure options in Photorec and leave it restoring what it can!