Ubuntu18のaptでインストールしたpip3ではtargetオプションを使ってもExceptionが発生する(Ubuntu18.04)

$ pip3 -V
pip 9.0.1 from /usr/lib/python3/dist-packages (python 3.6)

$ pip3 install requests -t workspace/
Collecting requests
  Using cached https://files.pythonhosted.org/packages/51/bd/23c926cd341ea6b7dd0b2a00aba99ae0f828be89d72b2190f27c11d4b7fb/requests-2.22.0-py2.py3-none-any.whl
Collecting chardet<3.1.0,>=3.0.2 (from requests)
  Using cached https://files.pythonhosted.org/packages/bc/a9/01ffebfb562e4274b6487b4bb1ddec7ca55ec7510b22e4c51f14098443b8/chardet-3.0.4-py2.py3-none-any.whl
Collecting urllib3!=1.25.0,!=1.25.1,<1.26,>=1.21.1 (from requests)
  Using cached https://files.pythonhosted.org/packages/81/b7/cef47224900ca67078ed6e2db51342796007433ad38329558f56a15255f5/urllib3-1.25.5-py2.py3-none-any.whl
Collecting certifi>=2017.4.17 (from requests)
  Using cached https://files.pythonhosted.org/packages/18/b0/8146a4f8dd402f60744fa380bc73ca47303cccf8b9190fd16a827281eac2/certifi-2019.9.11-py2.py3-none-any.whl
Collecting idna<2.9,>=2.5 (from requests)
  Using cached https://files.pythonhosted.org/packages/14/2c/cd551d81dbe15200be1cf41cd03869a46fe7226e7450af7a6545bfc474c9/idna-2.8-py2.py3-none-any.whl
Installing collected packages: chardet, urllib3, certifi, idna, requests
Exception:
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/pip/basecommand.py", line 215, in main
  status = self.run(options, args)
  File "/usr/lib/python3/dist-packages/pip/commands/install.py", line 360, in run
  prefix=options.prefix_path,
  File "/usr/lib/python3/dist-packages/pip/req/req_set.py", line 784, in install
  **kwargs
  File "/usr/lib/python3/dist-packages/pip/req/req_install.py", line 851, in install
  self.move_wheel_files(self.source_dir, root=root, prefix=prefix)
  File "/usr/lib/python3/dist-packages/pip/req/req_install.py", line 1064, in move_wheel_files
  isolated=self.isolated,
  File "/usr/lib/python3/dist-packages/pip/wheel.py", line 247, in move_wheel_files
  prefix=prefix,
  File "/usr/lib/python3/dist-packages/pip/locations.py", line 153, in distutils_scheme
  i.finalize_options()
  File "/usr/lib/python3.6/distutils/command/install.py", line 274, in finalize_options
  raise DistutilsOptionError("can't combine user with prefix, "
distutils.errors.DistutilsOptionError: can't combine user with prefix, exec_prefix/home, or install_(plat)base

sudo apt install python3-venv

python3 -m venv /path/to/target/env_dir

cd /path/to/target/env_dir
source bin/activate

pip install -U pip

pip install --install-option="--install-purelib=/python/packages" package_name