factory.common: line 78 contains this “bundled” use of fastboot
$("${FASTBOOT_BIN}" devices
The problem also occurred here Install e on fairphone 4 - #15 by florent.wehrli. The install seemed problematic even after eliminating that error. (User error ?? – strange “flow” in that thread ??)
At your new “fail point” the actual flashing depends on “flash or abort” so there is no error message in the event any one partition fails to flash. Very often a fail to flash like this will resolve on a second or third attempt.
… or something else is wrong ! Did you check the sha256sum of your download?
With two odd errors I would download again and be sure to check the sha256sum.
Meanwhile there have been comments, a forum search of ${FASTBOOT_BIN finds for instance Flashing script wrongfully claims the phone is still locked - #8 by Maryn.
I have to say that I am unsure and this accounts for my uncertainty when I first said
Please, perhaps, also confirm that you had met this in the Requirements section of the install page Install /e/OS on a Fairphone The Fairphone (Gen. 6) - “FP6”.
Check that
adbandfastbootare enabled on your PC. If not you can find the setup instructions here
… and the old one … check the full USB chain … best data cable, (for better transmission maybe “high capacity” ??) , generally avoid hubs (unless known and tested) beware the possibility of a hub hidden in a laptop, try to connect the USB cable to the PC/ laptop USB port soldered to the motherboard.
In this post Install e/OS on Fairphone 6 - #62 by poog72 use of correct USB port seemed to correct a problem where the install script started fine but then failed repeatedly to flash one partition and aborted.