Fix starting 'flit install' with statically specified PEP 621 metadata

flit/install.py

@@ -256,12 +256,12 @@ def install_requirements(self):
     def install_reqs_my_python_if_needed(self):
         """Install requirements to this environment if needed.
 
-        We can normally get the module's docstring and version number without
-        importing it, but if we do need to import it, we may need to install
+        We can normally get the summary and version number without import the
+        module, but if we do need to import it, we may need to install
         its requirements for the Python where flit is running.
         """
         try:
-            common.get_info_from_module(self.module)
+            common.get_info_from_module(self.module, self.ini_info.dynamic_metadata)
         except ImportError:
             if self.deps == 'none':
                 raise  # We were asked not to install deps, so bail out.

tests/test_install.py

@@ -183,6 +183,15 @@ def test_install_requires(self):
         assert len(calls) == 1
         assert calls[0]['argv'][1:5] == ['-m', 'pip', 'install', '-r']
 
+    def test_install_reqs_my_python_if_needed_pep621(self):
+        ins = Installer.from_ini_path(
+            core_samples_dir / 'pep621_nodynamic' / 'pyproject.toml',
+            deps='none',
+        )
+
+        # This shouldn't try to get version & docstring from the module
+        ins.install_reqs_my_python_if_needed()
+
     def test_extras_error(self):
         with pytest.raises(DependencyError):
             Installer.from_ini_path(samples_dir / 'requires-requests.toml',