allow not propagating components to consumers

conans/model/build_info.py

@@ -400,14 +400,6 @@ def _raise_incorrect_components_definition(self, package_name, package_requires)
 
         def _check_components_requires_instersection(comp_requires):
             reqs = [it.split(COMPONENT_SCOPE)[0] for it in comp_requires if COMPONENT_SCOPE in it]
-            # Raise on components requires without package requires
-            for pkg_require in pkg_requires:
-                if package_requires[pkg_require].private or package_requires[pkg_require].override:
-                    # Not standard requires, skip
-                    continue
-                if pkg_require not in reqs:
-                    raise ConanException("Package require '%s' not used in components requires"
-                                         % pkg_require)
             # Raise on components requires requiring inexistent package requires
             for comp_require in reqs:
                 reason = None

conans/test/functional/generators/components/propagate_specific_components_test.py

@@ -1,8 +1,6 @@
 import textwrap
 import unittest
 
-import pytest
-
 from conans.test.utils.tools import TestClient
 
 
@@ -133,25 +131,6 @@ def package_info(self):
             self.assertIn("ERROR: Component 'top::not-existing' not found in 'top'"
                           " package requirement", t.out)
 
-    def test_unused_requirement(self):
-        """ Requires should include all listed requirements
-            This error is known when creating the package if the requirement is consumed.
-        """
-        consumer = textwrap.dedent("""
-            from conans import ConanFile
-
-            class Recipe(ConanFile):
-                requires = "top/version"
-                def package_info(self):
-                    self.cpp_info.requires = ["other::other"]
-        """)
-        t = TestClient()
-        t.save({'top.py': self.top, 'consumer.py': consumer})
-        t.run('create top.py top/version@')
-        t.run('create consumer.py wrong/version@', assert_error=True)
-        self.assertIn("wrong/version package_info(): Package require 'top' not used"
-                      " in components requires", t.out)
-
     def test_wrong_requirement(self):
         """ If we require a wrong requirement, we get a meaninful error.
             This error is known when creating the package if the requirement is not there.

conans/test/functional/toolchains/cmake/cmakedeps/test_cmakedeps_components.py

@@ -116,26 +116,6 @@ def package_info(self):
     assert "Component 'top::not-existing' not found in 'top' package requirement" in t.out
 
 
-def test_unused_requirement(top_conanfile):
-    """ Requires should include all listed requirements
-        This error is known when creating the package if the requirement is consumed.
-    """
-    consumer = textwrap.dedent("""
-        from conans import ConanFile
-
-        class Recipe(ConanFile):
-            requires = "top/version"
-            def package_info(self):
-                self.cpp_info.requires = ["other::other"]
-    """)
-    t = TestClient()
-    t.save({'top.py': top_conanfile, 'consumer.py': consumer})
-    t.run('create top.py top/version@')
-    t.run('create consumer.py wrong/version@', assert_error=True)
-    assert "wrong/version package_info(): Package require 'top' not used in components " \
-           "requires" in t.out
-
-
 def test_wrong_requirement(top_conanfile):
     """ If we require a wrong requirement, we get a meaninful error.
         This error is known when creating the package if the requirement is not there.

conans/test/integration/generators/package_info/package_info_test.py

@@ -391,59 +391,6 @@ def test_package_requires_in_components_requires(self):
         client.run("create conanfile1.py")
         client.run("create conanfile2.py")
 
-        conanfile = GenConanfile("consumer", "0.1") \
-            .with_requirement("dep1/0.1") \
-            .with_requirement("dep2/0.1") \
-            .with_package_info(cpp_info={"components": {"kk": {"requires": []}}},
-                               env_info={})
-        client.save({"conanfile.py": conanfile})
-        client.run("create conanfile.py", assert_error=True)
-        self.assertIn("consumer/0.1 package_info(): Package require 'dep1' not used in "
-                      "components requires", client.out)
-
-        conanfile = GenConanfile("consumer", "0.1") \
-            .with_requirement("dep1/0.1") \
-            .with_requirement("dep2/0.1") \
-            .with_package_info(cpp_info={"components": {"kk": {"requires": ["dep1::dep1"]}}},
-                               env_info={})
-        client.save({"conanfile.py": conanfile})
-        client.run("create conanfile.py", assert_error=True)
-        self.assertIn("consumer/0.1 package_info(): Package require 'dep2' not used in components "
-                      "requires", client.out)
-
-        conanfile = GenConanfile("consumer", "0.1") \
-            .with_requirement("dep1/0.1") \
-            .with_requirement("dep2/0.1") \
-            .with_package_info(cpp_info={"components": {"kk": {"requires": ["dep1::dep1"]},
-                                                        "kkk": {"requires": ["kk"]}}},
-                               env_info={})
-        client.save({"conanfile.py": conanfile})
-        client.run("create conanfile.py", assert_error=True)
-        self.assertIn("consumer/0.1 package_info(): Package require 'dep2' not used in components "
-                      "requires", client.out)
-
-        conanfile = GenConanfile("consumer", "0.1") \
-            .with_requirement("dep1/0.1") \
-            .with_requirement("dep2/0.1") \
-            .with_package_info(cpp_info={"components": {"kk": {"requires": []},
-                                                        "kkk": {"requires": ["kk"]}}},
-                               env_info={})
-        client.save({"conanfile.py": conanfile})
-        client.run("create conanfile.py", assert_error=True)
-        self.assertIn("consumer/0.1 package_info(): Package require 'dep1' not used in components "
-                      "requires", client.out)
-
-        conanfile = GenConanfile("consumer", "0.1") \
-            .with_requirement("dep1/0.1") \
-            .with_requirement("dep2/0.1") \
-            .with_package_info(cpp_info={"components": {"kk": {"requires": ["dep2::comp"]},
-                                                        "kkk": {"requires": ["dep3::dep3"]}}},
-                               env_info={})
-        client.save({"conanfile.py": conanfile})
-        client.run("create conanfile.py", assert_error=True)
-        self.assertIn("consumer/0.1 package_info(): Package require 'dep1' not used in components "
-                      "requires", client.out)
-
         conanfile = GenConanfile("consumer", "0.1") \
             .with_requirement("dep2/0.1") \
             .with_package_info(cpp_info={"components": {"kk": {"requires": ["dep2::comp"]},

conans/test/integration/test_components.py

@@ -1,5 +1,6 @@
 import textwrap
 
+from conans.test.assets.genconanfile import GenConanfile
 from conans.test.utils.tools import TestClient
 
 
@@ -23,3 +24,27 @@ def package_info(self):
     assert "a requires c"
     assert "b requires a"
     assert "c rquires b"
+
+
+def test_components_not_required():
+    """
+    Allow requiring and building against one component, but not propagating it
+    https://github.com/conan-io/conan/issues/12965
+    """
+    c = TestClient()
+    conanfile = textwrap.dedent("""
+        from conan import ConanFile
+
+        class TestcycleConan(ConanFile):
+            name = "wayland"
+            version = "1.0"
+            requires = "expat/1.0"
+
+            def package_info(self):
+                self.cpp_info.components["wayland-scanner"].libdirs = []
+        """)
+    c.save({"expat/conanfile.py": GenConanfile("expat", "1.0"),
+            "wayland/conanfile.py": conanfile})
+    c.run("create expat")
+    c.run("create wayland")
+    assert "wayland/1.0: Created package" in c.out