[ty] Improve tracebacks when installing dependencies fails in ty_benchmark (#22399)

scripts/ty_benchmark/src/benchmark/projects.py

@@ -92,7 +92,7 @@ class Project(NamedTuple):
             )
 
         except subprocess.CalledProcessError as e:
-            raise RuntimeError(f"Failed to clone {self.name}: {e.stderr}")
+            raise RuntimeError(f"Failed to clone {self.name}:\n\n{e.stderr}") from e
 
         logging.info(f"Cloned {self.name} to {checkout_dir}.")
 

scripts/ty_benchmark/src/benchmark/run.py

@@ -147,7 +147,9 @@ def main() -> None:
             cwd = Path(tempdir)
             project.clone(cwd)
 
-            venv = Venv.create(cwd, project.python_version)
+            venv = Venv.create(
+                project=project.name, parent=cwd, python_version=project.python_version
+            )
             venv.install(project.install_arguments)
 
             commands = []

scripts/ty_benchmark/src/benchmark/test_lsp_diagnostics.py

@@ -42,7 +42,9 @@ def project_setup(
         cwd = Path(tempdir)
         project.clone(cwd)
 
-        venv = Venv.create(cwd, project.python_version)
+        venv = Venv.create(
+            project=project.name, parent=cwd, python_version=project.python_version
+        )
         venv.install(project.install_arguments)
 
         yield project, venv

scripts/ty_benchmark/src/benchmark/venv.py

@@ -3,15 +3,15 @@ from __future__ import annotations
 import logging
 import subprocess
 import sys
+from dataclasses import dataclass
 from pathlib import Path
 
 
+@dataclass(frozen=True, kw_only=True, slots=True)
 class Venv:
+    project_name: str
     project_path: Path
 
-    def __init__(self, path: Path):
-        self.project_path = path
-
     @property
     def path(self) -> Path:
         return self.project_path / "venv"
@@ -36,7 +36,7 @@ class Venv:
         return self.bin / f"{name}{extension}"
 
     @staticmethod
-    def create(parent: Path, python_version: str) -> Venv:
+    def create(*, project: str, parent: Path, python_version: str) -> Venv:
         """Creates a new, empty virtual environment."""
 
         command = [
@@ -53,9 +53,10 @@ class Venv:
                 command, cwd=parent, check=True, capture_output=True, text=True
             )
         except subprocess.CalledProcessError as e:
-            raise RuntimeError(f"Failed to create venv: {e.stderr}")
+            msg = f"Failed to create venv for {project}:\n\n{e.stderr}"
+            raise RuntimeError(msg) from e
 
-        return Venv(parent)
+        return Venv(project_name=project, project_path=parent)
 
     def install(self, pip_install_args: list[str]) -> None:
         """Installs the dependencies required to type check the project."""
@@ -87,4 +88,7 @@ class Venv:
                 text=True,
             )
         except subprocess.CalledProcessError as e:
-            raise RuntimeError(f"Failed to install dependencies: {e.stderr}")
+            msg = (
+                f"Failed to install dependencies for {self.project_name}:\n\n{e.stderr}"
+            )
+            raise RuntimeError(msg) from e