fix: write installer metadata

news/3359.feature.md

@@ -0,0 +1 @@
+Write installer metadata like `INSTALLER` and `REQUESTED` to dist-info directory when installing packages.

src/pdm/installers/base.py

@@ -2,6 +2,7 @@
 
 import dataclasses
 from functools import cached_property
+from itertools import chain
 from typing import Collection, Iterable
 
 from pdm import termui
@@ -90,6 +91,10 @@ def self_candidate(self) -> Candidate:
     def candidates(self) -> dict[str, Candidate]:
         """Return the candidates to be installed"""
         candidates = self.requested_candidates.copy()
+        requested = {
+            req.identify()
+            for req in (self.requirements or chain.from_iterable(self.environment.project.all_dependencies.values()))
+        }
         if isinstance(self.no_editable, Collection):
             keys = self.no_editable
         elif self.no_editable:
@@ -107,6 +112,9 @@ def candidates(self) -> dict[str, Candidate]:
                 # Create a new candidate with editable=False
                 req = dataclasses.replace(candidate.req, editable=False)
                 candidates[key] = candidate.copy_with(req)
+        for key in requested:
+            if key in candidates:
+                candidates[key].requested = True
         return candidates
 
     def should_install_editables(self) -> bool:

src/pdm/installers/installers.py

@@ -154,6 +154,7 @@ def install_wheel(
     direct_url: dict[str, Any] | None = None,
     install_links: bool = False,
     rename_pth: bool = False,
+    requested: bool = False,
 ) -> str:
     """Only create .pth files referring to the cached package.
     If the cache doesn't exist, create one.
@@ -169,9 +170,11 @@ def install_wheel(
     else:
         link_method = _get_link_method(cache_method)
 
-    additional_metadata: dict[str, bytes] = {}
+    additional_metadata: dict[str, bytes] = {"INSTALLER": b"pdm"}
     if direct_url is not None:
         additional_metadata["direct_url.json"] = json.dumps(direct_url, indent=2).encode()
+    if requested:
+        additional_metadata["REQUESTED"] = b""
 
     destination = InstallDestination(
         scheme_dict=environment.get_paths(dist_name),

src/pdm/installers/manager.py

@@ -35,6 +35,7 @@ def install(self, candidate: Candidate) -> Distribution:
             direct_url=prepared.direct_url(),
             install_links=self.use_install_cache and not candidate.req.editable,
             rename_pth=self.rename_pth,
+            requested=candidate.requested,
         )
         return Distribution.at(dist_info)
 

src/pdm/models/candidates.py

@@ -128,6 +128,7 @@ class Candidate:
         "link",
         "name",
         "req",
+        "requested",
         "summary",
         "version",
     )
@@ -153,6 +154,7 @@ def __init__(
         self.link = link
         self.summary = ""
         self.hashes: list[FileHash] = []
+        self.requested = False
 
         self._requires_python: str | None = None
         self._prepared: PreparedCandidate | None = None

src/pdm/pytest.py

@@ -328,7 +328,7 @@ def build_env(build_env_wheels: Iterable[Path], tmp_path_factory: pytest.TempPat
     p = Core().create_project(d)
     env = PythonEnvironment(p, prefix=str(d), python=sys.executable)
     for wheel in build_env_wheels:
-        install_wheel(wheel, env)
+        install_wheel(wheel, env, requested=True)
     return d