Avoid race conditions when installing multiple dependencies from the same git repository.

src/poetry/installation/executor.py

@@ -6,6 +6,7 @@
 import json
 import threading
 
+from collections import defaultdict
 from concurrent.futures import ThreadPoolExecutor
 from concurrent.futures import wait
 from pathlib import Path
@@ -144,6 +145,7 @@ def execute(self, operations: list[Operation]) -> int:
         for _, group in groups:
             tasks = []
             serial_operations = []
+            serial_git_operations = defaultdict(list)
             for operation in group:
                 if self._shutdown:
                     break
@@ -158,11 +160,36 @@ def execute(self, operations: list[Operation]) -> int:
                     operation.package.develop
                     and operation.package.source_type in {"directory", "git"}
                 )
-                if not operation.skipped and is_parallel_unsafe:
+                # Skipped operations are safe to execute in parallel
+                if operation.skipped:
+                    is_parallel_unsafe = False
+
+                if is_parallel_unsafe:
                     serial_operations.append(operation)
-                    continue
+                elif operation.package.source_type == "git":
+                    # Git operations on the same repository should be executed serially
+                    serial_git_operations[operation.package.source_url].append(
+                        operation
+                    )
+                else:
+                    tasks.append(
+                        self._executor.submit(self._execute_operation, operation)
+                    )
 
-                tasks.append(self._executor.submit(self._execute_operation, operation))
+            def _serialize(
+                repository_serial_operations: list[Operation],
+            ) -> None:
+                for operation in repository_serial_operations:
+                    self._execute_operation(operation)
+
+            # For each git repository, execute all operations serially
+            for repository_git_operations in serial_git_operations.values():
+                tasks.append(
+                    self._executor.submit(
+                        _serialize,
+                        repository_serial_operations=repository_git_operations,
+                    )
+                )
 
             try:
                 wait(tasks)

tests/installation/test_executor.py

@@ -1081,6 +1081,49 @@ def test_executor_should_append_subdirectory_for_git(
     assert archive_arg == tmp_venv.path / "src/demo/subdirectories/two"
 
 
+def test_executor_should_install_multiple_packages_from_same_git_repository(
+    mocker: MockerFixture,
+    tmp_venv: VirtualEnv,
+    pool: RepositoryPool,
+    config: Config,
+    artifact_cache: ArtifactCache,
+    io: BufferedIO,
+    wheel: Path,
+) -> None:
+    package_a = Package(
+        "package_a",
+        "0.1.2",
+        source_type="git",
+        source_reference="master",
+        source_resolved_reference="123456",
+        source_url="https://github.com/demo/subdirectories.git",
+        source_subdirectory="package_a",
+    )
+    package_b = Package(
+        "package_b",
+        "0.1.2",
+        source_type="git",
+        source_reference="master",
+        source_resolved_reference="123456",
+        source_url="https://github.com/demo/subdirectories.git",
+        source_subdirectory="package_b",
+    )
+
+    chef = Chef(artifact_cache, tmp_venv, Factory.create_pool(config))
+    chef.set_directory_wheel(wheel)
+    spy = mocker.spy(chef, "prepare")
+
+    executor = Executor(tmp_venv, pool, config, io)
+    executor._chef = chef
+    executor.execute([Install(package_a), Install(package_b)])
+
+    archive_arg = spy.call_args_list[0][0][0]
+    assert archive_arg == tmp_venv.path / "src/demo/subdirectories/package_a"
+
+    archive_arg = spy.call_args_list[1][0][0]
+    assert archive_arg == tmp_venv.path / "src/demo/subdirectories/package_b"
+
+
 def test_executor_should_write_pep610_url_references_for_git_with_subdirectories(
     tmp_venv: VirtualEnv,
     pool: RepositoryPool,