improved logging in case of run_python failure

tests/import_hook/common.py

@@ -16,7 +16,6 @@
 
 verbose = True
 
-
 script_dir = Path(__file__).resolve().parent
 maturin_dir = script_dir.parent.parent
 test_crates = maturin_dir / "test-crates"
@@ -30,7 +29,6 @@
 import_hook.install()
 """
 
-
 EXCLUDED_PROJECTS = {
     "hello-world",  # not imported as a python module (subprocess only)
     "license-test",  # not imported as a python module (subprocess only)
@@ -88,16 +86,18 @@ def run_python(
             message = "\n".join(
                 [
                     "-" * 40,
-                    "ERROR:",
+                    "Called Process Error:",
                     subprocess.list2cmdline(cmd),
-                    "",
+                    "Output:",
                     output,
                     "-" * 40,
                 ]
             )
-            print(message, file=sys.stderr)
+            print(message)
         if not expect_error:
-            raise
+            # re-raising the CalledProcessError would cause
+            # unnecessary output since we are already printing it above
+            raise RuntimeError("run_python failed") from None
     duration = time.perf_counter() - start
 
     output = output.replace("\r\n", "\n")
@@ -188,6 +188,15 @@ def is_installed_correctly(project_name: str, project_dir: Path, is_mixed: bool)
         f"checking if {project_name} is installed correctly. "
         f"{is_mixed=}, {installed_as_pth=} {installed_editable_with_direct_url=}"
     )
+
+    proc = subprocess.run(
+        [sys.executable, "-m", "pip", "show", "--disable-pip-version-check", "-f", project_name],
+        stdout=subprocess.PIPE,
+        stderr=subprocess.STDOUT,
+        check=False,
+    )
+    output = "None" if proc.stdout is None else proc.stdout.decode()
+    log(f"pip output (returned {proc.returncode}):\n{output}")
     return installed_editable_with_direct_url and (installed_as_pth == is_mixed)
 
 

tests/import_hook/test_project_importer.py

@@ -160,6 +160,7 @@ def test_do_not_rebuild_if_installed_non_editable(workspace: Path, project_name:
     uninstall(project_name)
     project_dir = get_project_copy(test_crates / project_name, workspace / project_name)
     install_non_editable(project_dir)
+    assert is_installed_correctly(project_name, project_dir, is_mixed="mixed" in project_name)
 
     check_installed_outside_project = workspace / "check_installed"
     check_installed_outside_project.mkdir()