Can't use the pmbootstrap newapkbuild

(015477) [21:25:43] % tail -f /home/bshah/src/PostmarketOS/cache/log.txt -n 60
(015477) [21:25:43] *** output passed to pmbootstrap stdout, not to this log ***
(015485) [21:25:46] (native) % rm -r /home/pmos/build
(015485) [21:25:46] (native) % busybox su pmos -c 'mkdir -p /home/pmos/build'
(015485) [21:25:46] (native) % cd /home/pmos/build && busybox su pmos -c 'newapkbuild -n kwayland-integration -d KWayland integration -C -f'
(015485) [21:25:46] *** output passed to pmbootstrap stdout, not to this log ***
(015485) [21:25:46] (native) % busybox su pmos -c 'mv /home/pmos/build/kwayland-integration/src /home/pmos/build'
(015485) [21:25:46] (native) % busybox su pmos -c 'mv /home/pmos/build/kwayland-integration/APKBUILD /home/pmos/build'
(015485) [21:25:46] (native) % busybox su pmos -c 'mv /home/pmos/build/kwayland-integration/kwayland-integration /home/pmos/build'
mv: can't rename '/home/pmos/build/kwayland-integration/kwayland-integration': Directory not empty
(015485) [21:25:46] ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
(015485) [21:25:46] NOTE: The failed command's output is above the ^^^ line in the logfile: /home/bshah/src/PostmarketOS/cache/log.txt
(015485) [21:25:46] ERROR: Command failed: (native) % busybox su pmos -c 'mv /home/pmos/build/kwayland-integration/kwayland-integration /home/pmos/build'
(015485) [21:25:46] Run 'pmbootstrap log' for details.
(015485) [21:25:46] See also: <https://postmarketos.org/troubleshooting>
(015485) [21:25:46] Traceback (most recent call last):
  File "/home/bshah/src/PostmarketOS/pmbootstrap/pmb/helpers/run.py", line 53, in core
    stderr=args.logfd)
  File "/usr/lib/python3.6/subprocess.py", line 291, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['sudo', '/usr/bin/sh', '-c', 'env -i CHARSET=UTF-8 PATH=/usr/lib/ccache/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin SHELL=/bin/ash HISTFILE=~/.ash_history /usr/bin/chroot /home/bshah/src/PostmarketOS/cache/chroot_native sh -c \'cd /;busybox su pmos -c \'"\'"\'mv /home/pmos/build/kwayland-integration/kwayland-integration /home/pmos/build\'"\'"\'\'']' returned non-zero exit status 1.

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/bshah/src/PostmarketOS/pmbootstrap/pmb/__init__.py", line 61, in main
    getattr(frontend, args.action)(args)
  File "/home/bshah/src/PostmarketOS/pmbootstrap/pmb/helpers/frontend.py", line 224, in newapkbuild
    pmb.build.newapkbuild(args, args.folder, args.args_passed)
  File "/home/bshah/src/PostmarketOS/pmbootstrap/pmb/build/newapkbuild.py", line 51, in newapkbuild
    pmb.chroot.user(args, ["mv", path_inside, build])
  File "/home/bshah/src/PostmarketOS/pmbootstrap/pmb/chroot/user.py", line 34, in user
    auto_init, return_stdout, check)
  File "/home/bshah/src/PostmarketOS/pmbootstrap/pmb/chroot/root.py", line 86, in root
    return_stdout, check)
  File "/home/bshah/src/PostmarketOS/pmbootstrap/pmb/helpers/run.py", line 66, in core
    raise RuntimeError("Command failed: " + log_message) from exc
RuntimeError: Command failed: (native) % busybox su pmos -c 'mv /home/pmos/build/kwayland-integration/kwayland-integration /home/pmos/build'

Command used:

./pmbootstrap.py newapkbuild kde -n kwayland-integration -d 'KWayland integration' -C -f

(I also tried without -f)