Additional logging to get context

src/pip/_internal/locations/__init__.py

@@ -44,16 +44,30 @@ def _default_base(*, user):
 
 
 def _warn_if_mismatch(old, new, *, key):
-    # type: (pathlib.Path, pathlib.Path, str) -> None
+    # type: (pathlib.Path, pathlib.Path, str) -> bool
     if old == new:
-        return
+        return False
     issue_url = "https://github.com/pypa/pip/issues/9617"
     message = (
-        "Value for %s does not match. Please report this to %s"
+        "Value for %s does not match. Please report this to <%s>"
         "\ndistutils: %s"
         "\nsysconfig: %s"
     )
     logger.warning(message, key, issue_url, old, new)
+    return True
+
+
+def _log_context(
+    *,
+    user: bool = False,
+    home: Optional[str] = None,
+    root: Optional[str] = None,
+    prefix: Optional[str] = None,
+) -> None:
+    message = (
+        "Additional context:" "\nuser = %r" "\nhome = %r" "\nroot = %r" "\nprefix = %r"
+    )
+    logger.warning(message, user, home, root, prefix)
 
 
 def get_scheme(
@@ -83,11 +97,15 @@ def get_scheme(
     )
 
     base = prefix or home or _default_base(user=user)
+    warned = []
     for k in SCHEME_KEYS:
         # Extra join because distutils can return relative paths.
         old_v = pathlib.Path(base, getattr(old, k))
         new_v = pathlib.Path(getattr(new, k))
-        _warn_if_mismatch(old_v, new_v, key=f"scheme.{k}")
+        warned.append(_warn_if_mismatch(old_v, new_v, key=f"scheme.{k}"))
+
+    if any(warned):
+        _log_context(user=user, home=home, root=root, prefix=prefix)
 
     return old
 
@@ -96,7 +114,8 @@ def get_bin_prefix():
     # type: () -> str
     old = _distutils.get_bin_prefix()
     new = _sysconfig.get_bin_prefix()
-    _warn_if_mismatch(pathlib.Path(old), pathlib.Path(new), key="bin_prefix")
+    if _warn_if_mismatch(pathlib.Path(old), pathlib.Path(new), key="bin_prefix"):
+        _log_context()
     return old
 
 
@@ -105,7 +124,8 @@ def get_purelib():
     """Return the default pure-Python lib location."""
     old = _distutils.get_purelib()
     new = _sysconfig.get_purelib()
-    _warn_if_mismatch(pathlib.Path(old), pathlib.Path(new), key="purelib")
+    if _warn_if_mismatch(pathlib.Path(old), pathlib.Path(new), key="purelib"):
+        _log_context()
     return old
 
 
@@ -114,7 +134,8 @@ def get_platlib():
     """Return the default platform-shared lib location."""
     old = _distutils.get_platlib()
     new = _sysconfig.get_platlib()
-    _warn_if_mismatch(pathlib.Path(old), pathlib.Path(new), key="platlib")
+    if _warn_if_mismatch(pathlib.Path(old), pathlib.Path(new), key="platlib"):
+        _log_context()
     return old
 
 
@@ -123,16 +144,22 @@ def get_prefixed_libs(prefix):
     """Return the lib locations under ``prefix``."""
     old_pure, old_plat = _distutils.get_prefixed_libs(prefix)
     new_pure, new_plat = _sysconfig.get_prefixed_libs(prefix)
-    _warn_if_mismatch(
-        pathlib.Path(old_pure),
-        pathlib.Path(new_pure),
-        key="prefixed-purelib",
-    )
-    _warn_if_mismatch(
-        pathlib.Path(old_plat),
-        pathlib.Path(new_plat),
-        key="prefixed-platlib",
-    )
+
+    warned = [
+        _warn_if_mismatch(
+            pathlib.Path(old_pure),
+            pathlib.Path(new_pure),
+            key="prefixed-purelib",
+        ),
+        _warn_if_mismatch(
+            pathlib.Path(old_plat),
+            pathlib.Path(new_plat),
+            key="prefixed-platlib",
+        ),
+    ]
+    if any(warned):
+        _log_context(prefix=prefix)
+
     if old_pure == old_plat:
         return [old_pure]
     return [old_pure, old_plat]