fix: uv 'extra-marker' markers in dependency groups

e2e/cases/BUILD.bazel

@@ -66,6 +66,17 @@ write_source_files(
         # lower-bound check that the file still gets emitted with no entries.
         "snapshots/project_single.private.markers.BUILD.bazel": "@project__single_project_hub//private/markers:BUILD.bazel",
 
+        # uv_project: extra activated through a dependency group. The `ci`
+        # group requests the project's own `build` extra (extra-marker[build]),
+        # which pulls in colorama gated by `extra == 'build'`. That marker is
+        # tautological once the extra is active and must be resolved away, or
+        # colorama gets dropped at runtime. This snapshot pins the resolved
+        # shape: the sccs file depends on `//:colorama` directly. Regressing the
+        # fix reintroduces the `extra == 'build'` marker and a `select(... :empty)`
+        # gate, so it shows up here as a diff. (The markers-file shape — no
+        # decide_marker emitted — is already pinned by project_single above.)
+        "snapshots/extra_marker.private.sccs.BUILD.bazel": "@project__extra_marker//private/sccs:BUILD.bazel",
+
         # @whl_install for grpcio with bare linux_* wheels
         # ----------------------------------------------------------------
         # grpcio 1.80.0 ships bare linux_armv7l wheels alongside manylinux/

e2e/cases/MODULE.bazel

@@ -138,6 +138,7 @@ include("//uv-data-purelib:setup.MODULE.bazel")
 include("//uv-dup-lock-records:setup.MODULE.bazel")
 include("//uv-duplicate-whl-labels:setup.MODULE.bazel")
 include("//uv-exclusions:setup.MODULE.bazel")
+include("//uv-extra-marker:setup.MODULE.bazel")
 include("//uv-git-source:setup.MODULE.bazel")
 include("//uv-include-group:setup.MODULE.bazel")
 include("//uv-incompatible-wheel-source:setup.MODULE.bazel")

e2e/cases/uv-extra-marker/BUILD.bazel

@@ -0,0 +1,14 @@
+load("@aspect_rules_py//py:defs.bzl", "py_test")
+
+py_test(
+    name = "extra_marker",
+    srcs = [
+        "__test__.py",
+    ],
+    dep_group = "ci",
+    main = "__test__.py",
+    python_version = "3.11",
+    deps = [
+        "@pypi_uv_extra_marker//colorama",
+    ],
+)

e2e/cases/uv-extra-marker/__test__.py

@@ -0,0 +1,12 @@
+#!/usr/bin/env python3
+"""Reproduce omitted extra-only markers.
+
+The dev dependency group activates the project's `build` extra, which should
+make `colorama` available. If rules_py evaluates `extra == 'build'` to false
+because the active venv is named `dev`, the dependency is dropped and this
+import fails.
+"""
+
+import colorama
+
+print(f"colorama: {colorama.__file__}")

e2e/cases/uv-extra-marker/pyproject.toml

@@ -0,0 +1,15 @@
+[project]
+name = "extra-marker"
+version = "0.0.0"
+requires-python = ">=3.11"
+dependencies = []
+
+[project.optional-dependencies]
+build = [
+    "colorama",
+]
+
+[dependency-groups]
+ci = [
+    "extra-marker[build]",
+]

e2e/cases/uv-extra-marker/setup.MODULE.bazel

@@ -0,0 +1,8 @@
+uv = use_extension("@aspect_rules_py//uv:extensions.bzl", "uv")
+uv.declare_hub(hub_name = "pypi_uv_extra_marker")
+uv.project(
+    hub_name = "pypi_uv_extra_marker",
+    lock = "//uv-extra-marker:uv.lock",
+    pyproject = "//uv-extra-marker:pyproject.toml",
+)
+use_repo(uv, "project__extra_marker", "pypi_uv_extra_marker")

uv/private/extension/BUILD.bazel

@@ -3,6 +3,7 @@ load(":test_defs.bzl", "defs_test_suite")
 load(":test_dep_groups.bzl", "dep_groups_test_suite")
 load(":test_git_utils.bzl", "git_utils_test_suite")
 load(":test_graph_utils.bzl", "graph_utils_test_suite")
+load(":test_marker_simplify.bzl", "marker_simplify_test_suite")
 load(":test_projectfile.bzl", "projectfile_test_suite")
 
 defs_test_suite()
@@ -13,6 +14,8 @@ git_utils_test_suite()
 
 graph_utils_test_suite()
 
+marker_simplify_test_suite()
+
 projectfile_test_suite()
 
 bzl_library(
@@ -57,6 +60,7 @@ bzl_library(
     visibility = ["//uv:__subpackages__"],
     deps = [
         ":git_utils",
+        ":marker_simplify",
         "//uv/private:normalize_name",
         "//uv/private:normalize_version",
         "//uv/private:parse_whl_name",
@@ -67,6 +71,13 @@ bzl_library(
     ],
 )
 
+bzl_library(
+    name = "marker_simplify",
+    srcs = ["marker_simplify.bzl"],
+    visibility = ["//uv:__subpackages__"],
+    deps = ["//uv/private/markers:pep508_evaluate"],
+)
+
 bzl_library(
     name = "projectfile",
     srcs = ["projectfile.bzl"],
@@ -119,6 +130,16 @@ bzl_library(
     ],
 )
 
+bzl_library(
+    name = "test_marker_simplify",
+    srcs = ["test_marker_simplify.bzl"],
+    visibility = ["//uv:__subpackages__"],
+    deps = [
+        ":marker_simplify",
+        "@bazel_skylib//lib:unittest",
+    ],
+)
+
 bzl_library(
     name = "test_projectfile",
     srcs = ["test_projectfile.bzl"],

uv/private/extension/lockfile.bzl

@@ -10,6 +10,7 @@ load("//uv/private/constraints/platform:defs.bzl", "supported_platform")
 load("//uv/private/constraints/python:defs.bzl", "supported_python")
 load("//uv/private/whl_install:repository.bzl", "compatible_python_tags")
 load(":git_utils.bzl", "parse_git_url", "try_git_to_http_archive")
+load(":marker_simplify.bzl", "simplify_extra_marker")
 
 def url_basename(url):
     """Returns the trailing file name of a distribution URL.
@@ -136,14 +137,18 @@ def build_marker_graph(lock_id, lock_data):
 
             graph.setdefault(ek, {})
             for dep in optional_deps:
+                marker = simplify_extra_marker(dep.get("marker", ""), extra_name)
+                if marker == None:
+                    continue
+
                 extras = dep.get("extra", ["__base__"])
                 if "__base__" not in extras:
                     extras = ["__base__"] + extras
 
                 for e in extras:
                     eek = (lock_id, dep["name"], dep["version"], e)
                     graph[ek].setdefault(eek, {})
-                    graph[ek][eek][dep.get("marker", "")] = 1
+                    graph[ek][eek][marker] = 1
 
     return graph
 

uv/private/extension/marker_simplify.bzl

@@ -0,0 +1,32 @@
+"""Partial evaluation of PEP 508 `extra` markers during graph construction.
+
+uv writes every dependency of an extra with a redundant `extra == '<name>'`
+marker. An edge out of an extra pseudo-package is only ever traversed once that
+extra is active, so once we know which extra an edge belongs to that clause is a
+known boolean. We resolve it here rather than emitting an un-evaluable
+`decide_marker`, which would later see an empty `extra` environment (the venv
+name is not the extra) and wrongly drop the dependency.
+"""
+
+load("//uv/private/markers:pep508_evaluate.bzl", "evaluate")
+
+def simplify_extra_marker(marker, extra):
+    """Partially evaluate a marker binding the `extra` PEP 508 variable.
+
+    Args:
+        marker: The PEP 508 marker string on the edge.
+        extra: The name of the active extra the edge belongs to.
+
+    Returns:
+        - `""` if the marker reduces to true.
+        - `None` if it reduces to false (the clause names a different extra).
+        - The residual marker string when other (e.g. platform) clauses remain.
+    """
+    if not marker:
+        return marker
+    res = evaluate(marker, env = {"extra": extra}, strict = False)
+    if res == False:
+        return None
+    if res == True:
+        return ""
+    return res

uv/private/extension/test_marker_simplify.bzl

@@ -0,0 +1,35 @@
+"""Tests for marker_simplify.bzl."""
+
+load("@bazel_skylib//lib:unittest.bzl", "asserts", "unittest")
+load(":marker_simplify.bzl", "simplify_extra_marker")
+
+def _simplify_extra_marker_test_impl(ctx):
+    env = unittest.begin(ctx)
+
+    # Markers without `extra` pass through, re-rendered with normalized quoting.
+    asserts.equals(env, "", simplify_extra_marker("", "build"))
+    asserts.equals(env, "sys_platform == \"win32\"", simplify_extra_marker("sys_platform == 'win32'", "build"))
+
+    # A matching extra collapses the marker to true ("").
+    asserts.equals(env, "", simplify_extra_marker("extra == 'build'", "build"))
+
+    # A non-matching extra collapses to false (None), dropping the edge.
+    asserts.equals(env, None, simplify_extra_marker("extra == 'build'", "other"))
+
+    # Mixed markers reduce to their platform residual, or vanish per the extra.
+    asserts.equals(env, "sys_platform == \"win32\"", simplify_extra_marker("extra == 'build' and sys_platform == 'win32'", "build"))
+    asserts.equals(env, None, simplify_extra_marker("extra == 'build' and sys_platform == 'win32'", "other"))
+    asserts.equals(env, "", simplify_extra_marker("extra == 'build' or sys_platform == 'win32'", "build"))
+    asserts.equals(env, "sys_platform == \"win32\"", simplify_extra_marker("extra == 'build' or sys_platform == 'win32'", "other"))
+
+    return unittest.end(env)
+
+simplify_extra_marker_test = unittest.make(
+    _simplify_extra_marker_test_impl,
+)
+
+def marker_simplify_test_suite():
+    unittest.suite(
+        "marker_simplify_tests",
+        simplify_extra_marker_test,
+    )