Funtoo fchroot 1.0.1 ("Valley of the Moles")
Copyright 2020-2022 Funtoo Solutions, Inc.; Licensed under the Apache License, Version 2.0

gcc -static -O2 -s -o /root/ffs-repo/usr/local/bin/qemu-arm-64bit-wrapper /root/ffs-repo/usr/local/bin/qemu-arm-64bit-wrapper.c
Traceback (most recent call last):
  File "/usr/lib/python3.9/site-packages/fchroot/binfmt.py", line 194, in register_binfmt
    with open("/proc/sys/fs/binfmt_misc/register", "w") as f:
FileNotFoundError: [Errno 2] No such file or directory: '/proc/sys/fs/binfmt_misc/register'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python-exec/python3.9/fchroot", line 219, in <module>
    main()
  File "/usr/lib/python-exec/python3.9/fchroot", line 213, in main
    manager = ChrootManager()
  File "/usr/lib/python-exec/python3.9/fchroot", line 121, in __init__
    binfmt.setup_wrapper(self.chroot_path, self.fchroot_arch)
  File "/usr/lib/python3.9/site-packages/fchroot/binfmt.py", line 228, in setup_wrapper
    register_binfmt(arch_desc, chroot_qemu_path)
  File "/usr/lib/python3.9/site-packages/fchroot/binfmt.py", line 201, in register_binfmt
    raise QEMUWrapperException("Was unable to write to /proc/sys/fs/binfmt_misc/register.")
fchroot.binfmt.QEMUWrapperException: Was unable to write to /proc/sys/fs/binfmt_misc/register.
Error encountered -- exit code 256
Test failure: step fchroot failed.

alkaline-dev-1 /home/oleg/ffs # ls /proc/sys/fs/binfmt_misc/
arm-64bit  register  status

alkaline-dev-1 /home/oleg/ffs # lxc exec ffs-oleg-arm-64bit-gnu-test /bin/bash
ffs-oleg-arm-64bit-gnu-test ~ #
ffs-oleg-arm-64bit-gnu-test ~ # ls /proc/sys/fs/binfmt_misc/
ffs-oleg-arm-64bit-gnu-test ~ #