Why `pyvenv` does not install `python-config`?

Well, after one year it's time to answer my own question :-)

Here follows the python-config script that is installed by virtualenv into ${VENV}/bin. If you use python3 -m venv ${VENV}, then just copy it into this location manually until this issue gets fixed (NB there's a bug report from 2011 still without a fix as far as I can tell).

#!/usr/bin/env python3"""This python-config script was taken from a virtual environmentcreated by `virtualenv`.The only change is the hash-bang line.The user shall copy this to ${VENV}/bin during setup.:author: unknown + AA:date: 2018-02-23"""import sysimport getoptimport sysconfigvalid_opts = ['prefix', 'exec-prefix', 'includes', 'libs', 'cflags',              'ldflags', 'help']if sys.version_info >= (3, 2):    valid_opts.insert(-1, 'extension-suffix')    valid_opts.append('abiflags')if sys.version_info >= (3, 3):    valid_opts.append('configdir')def exit_with_usage(code=1):    sys.stderr.write("Usage: {0} [{1}]\n".format(        sys.argv[0], '|'.join('--'+opt for opt in valid_opts)))    sys.exit(code)try:    opts, args = getopt.getopt(sys.argv[1:], '', valid_opts)except getopt.error:    exit_with_usage()if not opts:    exit_with_usage()pyver = sysconfig.get_config_var('VERSION')getvar = sysconfig.get_config_varopt_flags = [flag for (flag, val) in opts]if '--help' in opt_flags:    exit_with_usage(code=0)for opt in opt_flags:    if opt == '--prefix':        print(sysconfig.get_config_var('prefix'))    elif opt == '--exec-prefix':        print(sysconfig.get_config_var('exec_prefix'))    elif opt in ('--includes', '--cflags'):        flags = ['-I' + sysconfig.get_path('include'),                 '-I' + sysconfig.get_path('platinclude')]        if opt == '--cflags':            flags.extend(getvar('CFLAGS').split())        print(' '.join(flags))    elif opt in ('--libs', '--ldflags'):        abiflags = getattr(sys, 'abiflags', '')        libs = ['-lpython' + pyver + abiflags]        libs += getvar('LIBS').split()        libs += getvar('SYSLIBS').split()        # add the prefix/lib/pythonX.Y/config dir, but only if there is no        # shared library in prefix/lib/.        if opt == '--ldflags':            if not getvar('Py_ENABLE_SHARED'):                libs.insert(0, '-L' + getvar('LIBPL'))            if not getvar('PYTHONFRAMEWORK'):                libs.extend(getvar('LINKFORSHARED').split())        print(' '.join(libs))    elif opt == '--extension-suffix':        ext_suffix = sysconfig.get_config_var('EXT_SUFFIX')        if ext_suffix is None:            ext_suffix = sysconfig.get_config_var('SO')        print(ext_suffix)    elif opt == '--abiflags':        if not getattr(sys, 'abiflags', None):            exit_with_usage()        print(sys.abiflags)    elif opt == '--configdir':        print(sysconfig.get_config_var('LIBPL'))