Fix pip install --target

news/4111.bugfix

@@ -0,0 +1 @@
+Fix ``pip install --target`` by making ``--target``, ``--user``, and ``--prefix`` mutually exclusive.

pip/commands/install.py

@@ -181,6 +181,11 @@ def run(self, options, args):
                     "Can not combine '--user' and '--prefix' as they imply "
                     "different installation locations"
                 )
+            if options.target_dir:
+                raise CommandError(
+                    "Can not combine '--user' and '--target' as they imply "
+                    "different installation locations"
+                )
             if virtualenv_no_global():
                 raise InstallationError(
                     "Can not perform a '--user' install. User site-packages "
@@ -191,6 +196,11 @@ def run(self, options, args):
 
         temp_target_dir = None
         if options.target_dir:
+            if options.prefix_path:
+                raise CommandError(
+                    "Can not combine '--target' and '--prefix' as they imply "
+                    "different installation locations"
+                )
             options.ignore_installed = True
             temp_target_dir = tempfile.mkdtemp()
             options.target_dir = os.path.abspath(options.target_dir)
@@ -201,6 +211,7 @@ def run(self, options, args):
                     "continue."
                 )
             install_options.append('--home=' + temp_target_dir)
+            install_options.append('--prefix=')
 
         global_options = options.global_options or []
 

pip/locations.py

@@ -151,9 +151,11 @@ def distutils_scheme(dist_name, user=False, home=None, root=None,
     # or user base for installations during finalize_options()
     # ideally, we'd prefer a scheme class that has no side-effects.
     assert not (user and prefix), "user={0} prefix={1}".format(user, prefix)
-    i.user = user or i.user
-    if user:
+    assert not (home and prefix), "home={0} prefix={1}".format(home, prefix)
+    assert not (home and user), "home={0} user={1}".format(home, user)
+    if user or home:
         i.prefix = ""
+    i.user = user or i.user
     i.prefix = prefix or i.prefix
     i.home = home or i.home
     i.root = root or i.root

tests/functional/test_install.py

@@ -663,6 +663,37 @@ def test_install_package_conflict_prefix_and_user(script, data):
     )
 
 
+def test_install_package_conflict_target_and_user(script, data):
+    """
+    Test installing a package using pip install --target --user errors out
+    """
+    target_path = script.scratch_path / 'target'
+    result = script.pip(
+        'install', '-f', data.find_links, '--no-index', '--user',
+        '--target', target_path, 'simple==1.0',
+        expect_error=True, quiet=True,
+    )
+    assert (
+        "Can not combine '--user' and '--target'" in result.stderr
+    )
+
+
+def test_install_package_conflict_prefix_and_target(script, data):
+    """
+    Test installing a package using pip install --prefix --targetx errors out
+    """
+    prefix_path = script.scratch_path / 'prefix'
+    target_path = script.scratch_path / 'target'
+    result = script.pip(
+        'install', '-f', data.find_links, '--no-index', '--target',
+        target_path, '--prefix', prefix_path, 'simple==1.0',
+        expect_error=True, quiet=True,
+    )
+    assert (
+        "Can not combine '--target' and '--prefix'" in result.stderr
+    )
+
+
 # skip on win/py3 for now, see issue #782
 @pytest.mark.skipif("sys.platform == 'win32' and sys.version_info >= (3,)")
 def test_install_package_that_emits_unicode(script, data):

tests/functional/test_install_reqs.py

@@ -222,6 +222,60 @@ def test_wheel_user_with_prefix_in_pydistutils_cfg(script, data, virtualenv):
     assert 'installed requiresupper' in result.stdout
 
 
+def test_nowheel_user_with_prefix_in_pydistutils_cfg(script, data, virtualenv):
+    virtualenv.system_site_packages = True
+    homedir = script.environ["HOME"]
+    script.scratch_path.join("bin").mkdir()
+    with open(os.path.join(homedir, ".pydistutils.cfg"), "w") as cfg:
+        cfg.write(textwrap.dedent("""
+            [install]
+            prefix=%s""" % script.scratch_path))
+
+    result = script.pip('install', '--no-binary=:all:', '--user', '--no-index',
+                        '-f', data.find_links, 'requiresupper',
+                        expect_stderr=True)
+    assert 'installed requiresupper' in result.stdout
+
+
+@pytest.mark.network
+def test_wheel_target_with_prefix_in_pydistutils_cfg(script, data,
+                                                     virtualenv):
+    # Make sure wheel is available in the virtualenv
+    script.pip('install', 'wheel')
+    virtualenv.system_site_packages = True
+    homedir = script.environ["HOME"]
+    script.scratch_path.join("bin").mkdir()
+    with open(os.path.join(homedir, ".pydistutils.cfg"), "w") as cfg:
+        cfg.write(textwrap.dedent("""
+            [install]
+            prefix=%s""" % script.scratch_path))
+
+    target_path = script.scratch_path / 'target'
+    result = script.pip('install', '--target', target_path, '--no-index', '-f',
+                        data.find_links, 'requiresupper')
+    # Check that we are really installing a wheel
+    assert 'Running setup.py install for requiresupper' not in result.stdout
+    assert 'installed requiresupper' in result.stdout
+
+
+def test_nowheel_target_with_prefix_in_pydistutils_cfg(script, data,
+                                                       virtualenv):
+    virtualenv.system_site_packages = True
+    homedir = script.environ["HOME"]
+    script.scratch_path.join("bin").mkdir()
+    with open(os.path.join(homedir, ".pydistutils.cfg"), "w") as cfg:
+        cfg.write(textwrap.dedent("""
+            [install]
+            prefix=%s""" % script.scratch_path))
+
+    target_path = script.scratch_path / 'target'
+    result = script.pip('install', '--no-binary=:all:',
+                        '--target', target_path,
+                        '--no-index', '-f', data.find_links, 'requiresupper',
+                        expect_stderr=True)
+    assert 'installed requiresupper' in result.stdout
+
+
 def test_install_option_in_requirements_file(script, data, virtualenv):
     """
     Test --install-option in requirements file overrides same option in cli