As a part of issue #18109

$ echo hât | sudo tee /proc/sys/kernel/hostname
$ hostname #Yes, I know about RFC952;-)
hât

$ locale
LANG=en_US.UTF-8
LANGUAGE=
LC_CTYPE=en_US.UTF-8
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES=POSIX
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=

$ make
...
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
  File "/home/d9frog9n/workspace/cpython_default/Lib/runpy.py", line 160, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "/home/d9frog9n/workspace/cpython_default/Lib/runpy.py", line 73, in _run_code
    exec(code, run_globals)
  File "/home/d9frog9n/workspace/cpython_default/Lib/sysconfig.py", line 700, in <module>
    _main()
  File "/home/d9frog9n/workspace/cpython_default/Lib/sysconfig.py", line 688, in _main
    _generate_posix_vars()
  File "/home/d9frog9n/workspace/cpython_default/Lib/sysconfig.py", line 391, in _generate_posix_vars
    pybuilddir = 'build/lib.%s-%s' % (get_platform(), sys.version[:3])
  File "/home/d9frog9n/workspace/cpython_default/Lib/sysconfig.py", line 632, in get_platform
    osname, host, release, version, machine = os.uname()
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 1: ordinal not in range(128)
make: *** [pybuilddir.txt] Error 1

Why open this issue, since it's obviously a duplicate of #18109?

Just a another behavior. My mistake, sorry.