Building coreboot from source (official script)

I’m still getting this error when I attempt to run the script on my Librem 15v3:

Built purism/librem15v3 (Librem 15 v3)
File build/coreboot.rom is 16777216 bytes
  Flash Region 0 (Flash Descriptor): 00000000 - 00000fff
  Flash Region 1 (BIOS): 00200000 - 00ffffff
  Flash Region 2 (Intel ME): 00001000 - 001fffff
  Flash Region 3 (GbE): 07fff000 - 00000fff (unused)
  Flash Region 4 (Platform Data): 07fff000 - 00000fff (unused)
  Flash Region 5 (Reserved): 07fff000 - 00000fff (unused)
  Flash Region 6 (Reserved): 07fff000 - 00000fff (unused)
  Flash Region 7 (Reserved): 07fff000 - 00000fff (unused)
  Flash Region 8 (EC): 07fff000 - 00000fff (unused)
HEAD is now at 9facf98... Change debug line to avoid confusion with new --extra-partitions argument
Full image detected
The ME/TXE region goes from 0x1000 to 0x200000
Found FPT header at 0x1010
Found 11 partition(s)
Found FTPR header: FTPR partition spans from 0x2000 to 0xa9000
Found FTPR manifest at 0x2478
ME/TXE firmware version 11.0.18.1002
Removing unused partitions...
 b'FTPR'         (0x1000   - 0xa8000  (0xa7000  total bytes)): removed
 b'FTUP'         (0x110000 - 0x1bc000 (0xac000  total bytes)): removed
 b'DLMP'         (0x0      - 0x0      (0x0      total bytes)): removed
 b'PSVN'         (0xe00    - 0x1000   (0x200    total bytes)): removed
 b'IVBP'         (0x10c000 - 0x110000 (0x4000   total bytes)): removed
 b'MFS\x00'      (0xa8000  - 0x10c000 (0x64000  total bytes)): removed
 b'NFTP'         (0x110000 - 0x1bc000 (0xac000  total bytes)): removed
 b'ROMB'         (0x0      - 0x0      (0x0      total bytes)): removed
 b'FLOG'         (0x1bc000 - 0x1bd000 (0x1000   total bytes)): removed
 b'UTOK'         (0x1bd000 - 0x1bf000 (0x2000   total bytes)): removed
 b'ISHC'         (0x0      - 0x0      (0x0      total bytes)): removed
Removing unused partition entries in FPT...
Traceback (most recent call last):
  File "./me_cleaner/me_cleaner.py", line 638, in <module>
    mef.write_to(me_start + 0x14, pack("<I", len(new_partitions) / 0x20))
struct.error: required argument is not an integer

I’m using Arch Linux, though I don’t believe thats the issue here. Any ideas?