fixed problem with transitive build_requires (#5056)

* fixed problem with transitive build_requires

* comment fix

conans/client/graph/graph_builder.py

@@ -148,6 +148,9 @@ def _handle_require(self, name, node, require, dep_graph, check_updates, update,
             new_node.inverse_closure.add(node)
             node.public_deps[new_node.name] = new_node
 
+            # If the parent node is a build-require, this new node will be a build-require
+            # If the requirement is a build-require, this node will also be a build-require
+            new_node.build_require = node.build_require or require.build_require
             # New nodes will inherit the private property of its ancestor
             new_node.private = node.private or require.private
             if require.private or require.build_require:

conans/test/functional/build_requires/build_requires_test.py

@@ -6,6 +6,7 @@
 from conans.paths import CONANFILE
 from conans.test.utils.tools import TestClient
 from conans.util.files import load
+from conans.test.utils.conanfile import TestConanFile
 
 tool_conanfile = """from conans import ConanFile
 
@@ -50,6 +51,20 @@ def build_requirements(self):
 
 
 class BuildRequiresTest(unittest.TestCase):
+    def test_build_requires_diamond(self):
+        t = TestClient()
+        t.save({"conanfile.py": str(TestConanFile("libA", "0.1"))})
+        t.run("create . libA/0.1@user/testing")
+
+        t.save({"conanfile.py": str(TestConanFile("libB", "0.1",
+                                                  requires=["libA/0.1@user/testing"]))})
+        t.run("create . libB/0.1@user/testing")
+
+        t.save({"conanfile.py": str(TestConanFile("libC", "0.1",
+                                                  build_requires=["libB/0.1@user/testing",
+                                                                  "libA/0.1@user/testing"]))})
+        t.run("create . libC/0.1@user/testing")
+        self.assertIn("libC/0.1@user/testing: Created package", t.out)
 
     def create_with_tests_and_build_requires_test(self):
         client = TestClient()

conans/test/functional/graph/graph_manager_test.py

@@ -768,7 +768,7 @@ def test_dont_conflict_private(self, private_first):
         self._check_node(liba2, "liba/0.2@user/testing#123", deps=[], build_deps=[],
                          dependents=[libc], closure=[])
 
-    def consecutive_private(self):
+    def test_consecutive_private(self):
         liba_ref = "liba/0.1@user/testing"
         libb_ref = "libb/0.1@user/testing"
         libc_ref = "libc/0.1@user/testing"