fix: Resolve incorrect platform specific dependency (bazel-contrib#2766)

This change addresses a bug where `pip.parse` selects the wrong
requirement entry when multiple extras are listed with platform-specific
markers.

#### 🔍 Problem:
In a `requirements.txt` generated by tools like `uv` or `poetry`, it's
valid to have multiple entries for the same package, each with different
extras and `sys_platform` markers, for example:

```ini
optimum[onnxruntime]==1.17.1 ; sys_platform == 'darwin'
optimum[onnxruntime-gpu]==1.17.1 ; sys_platform == 'linux'
```

The current implementation in
[`[parse_requirements.bzl](https://github.com/bazel-contrib/rules_python/blob/032f6aa738a673b13b605dabf55465c6fc1a56eb/python/private/pypi/parse_requirements.bzl#L114-L126)`](https://github.com/bazel-contrib/rules_python/blob/032f6aa738a673b13b605dabf55465c6fc1a56eb/python/private/pypi/parse_requirements.bzl#L114-L126)
uses a sort-by-length heuristic to select the “best” requirement when
there are multiple entries with the same base name. This works well in
legacy `requirements.txt` files where:
```
my_dep
my_dep[foo]
my_dep[foo,bar]
```
...would indicate an intent to select the **most specific subset of
extras** (i.e. the longest name).

However, this heuristic **breaks** in the presence of **platform
markers**, where extras are **not subsets**, but distinct variants. In
the example above, Bazel mistakenly selects `optimum[onnxruntime-gpu]`
on macOS because it's a longer match, even though it is guarded by a
Linux-only marker.

#### ✅ Fix:
This PR modifies the behavior to:
1. **Add the requirement marker** as part of the sorting key.
2. **Then apply the longest-match logic** to drop duplicate requirements
with different extras but the same markers.

This ensures that only applicable requirements are considered during
resolution, preserving correctness in multi-platform environments.

#### 🧪 Before:
On macOS, the following entry is incorrectly selected:
```
optimum[onnxruntime-gpu]==1.17.1 ; sys_platform == 'linux'
```

#### ✅ After:
Correct entry is selected:
```
optimum[onnxruntime]==1.17.1 ; sys_platform == 'darwin'
```

close bazel-contrib#2690

---------

Co-authored-by: Ignas Anikevicius <[email protected]>

Author: ewianda

CHANGELOG.md

@@ -81,6 +81,8 @@ Unreleased changes template.
 
 {#v0-0-0-fixed}
 ### Fixed
+* (pypi) Platform specific extras are now correctly handled when using
+  universal lock files with environment markers. Fixes [#2690](https://github.com/bazel-contrib/rules_python/pull/2690).
 * (runfiles) ({obj}`--bootstrap_impl=script`) Follow symlinks when searching for runfiles.
 * (toolchains) Do not try to run `chmod` when downloading non-windows hermetic toolchain
   repositories on Windows. Fixes

python/private/pypi/parse_requirements.bzl

@@ -30,22 +30,9 @@ load("//python/private:normalize_name.bzl", "normalize_name")
 load("//python/private:repo_utils.bzl", "repo_utils")
 load(":index_sources.bzl", "index_sources")
 load(":parse_requirements_txt.bzl", "parse_requirements_txt")
+load(":pep508_requirement.bzl", "requirement")
 load(":whl_target_platforms.bzl", "select_whls")
 
-def _extract_version(entry):
-    """Extract the version part from the requirement string.
-
-
-    Args:
-        entry: {type}`str` The requirement string.
-    """
-    version_start = entry.find("==")
-    if version_start != -1:
-        # Extract everything after '==' until the next space or end of the string
-        version, _, _ = entry[version_start + 2:].partition(" ")
-        return version
-    return None
-
 def parse_requirements(
         ctx,
         *,
@@ -111,19 +98,20 @@ def parse_requirements(
         # The requirement lines might have duplicate names because lines for extras
         # are returned as just the base package name. e.g., `foo[bar]` results
         # in an entry like `("foo", "foo[bar] == 1.0 ...")`.
-        requirements_dict = {
-            (normalize_name(entry[0]), _extract_version(entry[1])): entry
-            for entry in sorted(
-                parse_result.requirements,
-                # Get the longest match and fallback to original WORKSPACE sorting,
-                # which should get us the entry with most extras.
-                #
-                # FIXME @aignas 2024-05-13: The correct behaviour might be to get an
-                # entry with all aggregated extras, but it is unclear if we
-                # should do this now.
-                key = lambda x: (len(x[1].partition("==")[0]), x),
-            )
-        }.values()
+        # Lines with different markers are not condidered duplicates.
+        requirements_dict = {}
+        for entry in sorted(
+            parse_result.requirements,
+            # Get the longest match and fallback to original WORKSPACE sorting,
+            # which should get us the entry with most extras.
+            #
+            # FIXME @aignas 2024-05-13: The correct behaviour might be to get an
+            # entry with all aggregated extras, but it is unclear if we
+            # should do this now.
+            key = lambda x: (len(x[1].partition("==")[0]), x),
+        ):
+            req = requirement(entry[1])
+            requirements_dict[(req.name, req.version, req.marker)] = entry
 
         tokenized_options = []
         for opt in parse_result.options:
@@ -132,7 +120,7 @@ def parse_requirements(
 
         pip_args = tokenized_options + extra_pip_args
         for plat in plats:
-            requirements[plat] = requirements_dict
+            requirements[plat] = requirements_dict.values()
             options[plat] = pip_args
 
     requirements_by_platform = {}

python/private/pypi/pep508_requirement.bzl

@@ -30,6 +30,16 @@ def requirement(spec):
     """
     spec = spec.strip()
     requires, _, maybe_hashes = spec.partition(";")
+
+    version_start = requires.find("==")
+    version = None
+    if version_start != -1:
+        # Extract everything after '==' until the next space or end of the string
+        version, _, _ = requires[version_start + 2:].partition(" ")
+
+        # Remove any trailing characters from the version string
+        version = version.strip(" ")
+
     marker, _, _ = maybe_hashes.partition("--hash")
     requires, _, extras_unparsed = requires.partition("[")
     extras_unparsed, _, _ = extras_unparsed.partition("]")
@@ -42,4 +52,5 @@ def requirement(spec):
         name = normalize_name(name).replace("_", "-"),
         marker = marker.strip(" "),
         extras = extras,
+        version = version,
     )

tests/pypi/extension/extension_tests.bzl

@@ -856,6 +856,84 @@ git_dep @ git+https://git.server/repo/project@deadbeefdeadbeef
 
 _tests.append(_test_simple_get_index)
 
+def _test_optimum_sys_platform_extra(env):
+    pypi = _parse_modules(
+        env,
+        module_ctx = _mock_mctx(
+            _mod(
+                name = "rules_python",
+                parse = [
+                    _parse(
+                        hub_name = "pypi",
+                        python_version = "3.15",
+                        requirements_lock = "universal.txt",
+                    ),
+                ],
+            ),
+            read = lambda x: {
+                "universal.txt": """\
+optimum[onnxruntime]==1.17.1 ; sys_platform == 'darwin'
+optimum[onnxruntime-gpu]==1.17.1 ; sys_platform == 'linux'
+""",
+            }[x],
+        ),
+        available_interpreters = {
+            "python_3_15_host": "unit_test_interpreter_target",
+        },
+    )
+
+    pypi.exposed_packages().contains_exactly({"pypi": []})
+    pypi.hub_group_map().contains_exactly({"pypi": {}})
+    pypi.hub_whl_map().contains_exactly({
+        "pypi": {
+            "optimum": {
+                "pypi_315_optimum_linux_aarch64_linux_arm_linux_ppc_linux_s390x_linux_x86_64": [
+                    whl_config_setting(
+                        version = "3.15",
+                        target_platforms = [
+                            "cp315_linux_aarch64",
+                            "cp315_linux_arm",
+                            "cp315_linux_ppc",
+                            "cp315_linux_s390x",
+                            "cp315_linux_x86_64",
+                        ],
+                        config_setting = None,
+                        filename = None,
+                    ),
+                ],
+                "pypi_315_optimum_osx_aarch64_osx_x86_64": [
+                    whl_config_setting(
+                        version = "3.15",
+                        target_platforms = [
+                            "cp315_osx_aarch64",
+                            "cp315_osx_x86_64",
+                        ],
+                        config_setting = None,
+                        filename = None,
+                    ),
+                ],
+            },
+        },
+    })
+
+    pypi.whl_libraries().contains_exactly({
+        "pypi_315_optimum_linux_aarch64_linux_arm_linux_ppc_linux_s390x_linux_x86_64": {
+            "dep_template": "@pypi//{name}:{target}",
+            "python_interpreter_target": "unit_test_interpreter_target",
+            "repo": "pypi_315",
+            "requirement": "optimum[onnxruntime-gpu]==1.17.1",
+        },
+        "pypi_315_optimum_osx_aarch64_osx_x86_64": {
+            "dep_template": "@pypi//{name}:{target}",
+            "python_interpreter_target": "unit_test_interpreter_target",
+            "repo": "pypi_315",
+            "requirement": "optimum[onnxruntime]==1.17.1",
+        },
+    })
+    pypi.whl_mods().contains_exactly({})
+
+_tests.append(_test_optimum_sys_platform_extra)
+
 def extension_test_suite(name):
     """Create the test suite.
 

tests/pypi/pep508/requirement_tests.bzl

@@ -20,20 +20,21 @@ _tests = []
 
 def _test_requirement_line_parsing(env):
     want = {
-        " name1[ foo ] ": ("name1", ["foo"]),
-        "Name[foo]": ("name", ["foo"]),
-        "name [fred,bar] @ http://foo.com ; python_version=='2.7'": ("name", ["fred", "bar"]),
-        "name; (os_name=='a' or os_name=='b') and os_name=='c'": ("name", [""]),
-        "name@http://foo.com": ("name", [""]),
-        "name[ Foo123 ]": ("name", ["Foo123"]),
-        "name[extra]@http://foo.com": ("name", ["extra"]),
-        "name[foo]": ("name", ["foo"]),
-        "name[quux, strange];python_version<'2.7' and platform_version=='2'": ("name", ["quux", "strange"]),
-        "name_foo[bar]": ("name-foo", ["bar"]),
+        " name1[ foo ] ": ("name1", ["foo"], None, ""),
+        "Name[foo]": ("name", ["foo"], None, ""),
+        "name [fred,bar] @ http://foo.com ; python_version=='2.7'": ("name", ["fred", "bar"], None, "python_version=='2.7'"),
+        "name; (os_name=='a' or os_name=='b') and os_name=='c'": ("name", [""], None, "(os_name=='a' or os_name=='b') and os_name=='c'"),
+        "name@http://foo.com": ("name", [""], None, ""),
+        "name[ Foo123 ]": ("name", ["Foo123"], None, ""),
+        "name[extra]@http://foo.com": ("name", ["extra"], None, ""),
+        "name[foo]": ("name", ["foo"], None, ""),
+        "name[quux, strange];python_version<'2.7' and platform_version=='2'": ("name", ["quux", "strange"], None, "python_version<'2.7' and platform_version=='2'"),
+        "name_foo[bar]": ("name-foo", ["bar"], None, ""),
+        "name_foo[bar]==0.25": ("name-foo", ["bar"], "0.25", ""),
     }
 
     got = {
-        i: (parsed.name, parsed.extras)
+        i: (parsed.name, parsed.extras, parsed.version, parsed.marker)
         for i, parsed in {case: requirement(case) for case in want}.items()
     }
     env.expect.that_dict(got).contains_exactly(want)