Don't fail on skipped file/dir dependencies

src/poetry/installation/installer.py

@@ -335,7 +335,7 @@ def _do_install(self) -> int:
             dep = op.package.to_dependency()
             if dep.is_file() or dep.is_directory():
                 dep = cast("PathDependency", dep)
-                dep.validate(raise_error=True)
+                dep.validate(raise_error=not op.skipped)
 
         # Execute operations
         status = self._execute(ops)

tests/console/commands/test_install.py

@@ -470,6 +470,25 @@ def test_install_path_dependency_does_not_exist(
             tester.execute(options)
 
 
+@pytest.mark.parametrize("options", ["", "--extras notinstallable"])
+def test_install_extra_path_dependency_does_not_exist(
+    command_tester_factory: CommandTesterFactory,
+    project_factory: ProjectFactory,
+    fixture_dir: FixtureDirGetter,
+    options: str,
+) -> None:
+    project = "missing_extra_directory_dependency"
+    poetry = _project_factory(project, project_factory, fixture_dir)
+    assert isinstance(poetry.locker, TestLocker)
+    poetry.locker.locked(True)
+    tester = command_tester_factory("install", poetry=poetry)
+    if not options:
+        tester.execute(options)
+    else:
+        with pytest.raises(ValueError, match="does not exist"):
+            tester.execute(options)
+
+
 @pytest.mark.parametrize("options", ["", "--no-directory"])
 def test_install_missing_directory_dependency_with_no_directory(
     command_tester_factory: CommandTesterFactory,

tests/fixtures/missing_extra_directory_dependency/pyproject.toml

@@ -0,0 +1,14 @@
+[tool.poetry]
+name = "project-with-missing-extra-directory-dependency"
+version = "1.2.3"
+description = "This is a description"
+authors = ["Your Name <you@example.com>"]
+license = "MIT"
+packages = []
+
+[tool.poetry.dependencies]
+python = "*"
+missing = { path = "./missing", optional = true }
+
+[tool.poetry.extras]
+notinstallable = ["missing"]