Backport <host_version:track ref> to Conan v1

conans/client/graph/graph_builder.py

@@ -404,18 +404,29 @@ def _config_node(node, down_ref, down_options):
 
     def _resolve_recipe(self, current_node, dep_graph, requirement, check_updates,
                         update, remotes, profile, graph_lock, original_ref=None):
-
         ref = requirement.ref
-        if ref.version == "<host_version>":
+        ref_version = str(ref.version)
+        if ref_version.startswith("<host_version") and ref_version.endswith(">"):
             if not requirement.build_require:
                 raise ConanException(f"{current_node.ref} uses '<host_version>' in requires, "
                                      "it is only allowed in tool_requires")
+            search_ref_name = ref.name
+            tracking_ref = ref_version.split(":", 1)
+            if len(tracking_ref) == 2:
+                search_ref_name = tracking_ref[1][:-1]  # Remove trailing '>'
             transitive = next((dep for dep in current_node.dependencies if
-                  not dep.build_require and dep.require.ref.name == ref.name), None)
+                               not dep.build_require and
+                               dep.require.ref.name == search_ref_name and
+                               dep.require.ref.user == ref.user and
+                               dep.require.ref.channel == ref.channel), None)
             if transitive is None:
                 raise ConanException(
-                    f"{current_node.ref} require '{ref}': didn't find a matching host dependency")
-            requirement.ref = transitive.require.ref
+                    f"{current_node.ref} require '{search_ref_name}': didn't find a matching host dependency")
+            new_ref = transitive.require.ref
+            # Final ref is the one from the transitive dependency, but with the version from the
+            # tracked requirement, if any
+            requirement.ref = ConanFileReference(ref.name, new_ref.version,
+                                                 new_ref.user, new_ref.channel)
 
         try:
             result = self._proxy.get_recipe(requirement.ref, check_updates, update,

conans/model/ref.py

@@ -153,7 +153,8 @@ def validate_name(name, reference_token=None):
     @staticmethod
     def validate_version(version, pkg_name):
         ConanName.validate_string(version)
-        if version == "*" or version == "<host_version>":
+        version_str = str(version)
+        if version == "*" or (version_str.startswith("<host_version") and version_str.endswith(">")):
             return
         if ConanName._validation_pattern.match(version) is None:
             if (

conans/test/integration/build_requires/build_requires_test.py

@@ -616,7 +616,7 @@ def test_track_host_error_nothost(self, build_profile):
         c.save({"conanfile.py":
                 GenConanfile("pkg").with_build_requirement("protobuf/<host_version>")})
         c.run(f"install . {build_profile}", assert_error=True)
-        assert "'protobuf/<host_version>': didn't find a matching host dependency" in c.out
+        assert "pkg/None require 'protobuf': didn't find a matching host dependency" in c.out
 
     @pytest.mark.parametrize("build_profile", [False, True])
     def test_track_host_error_wrong_context(self, build_profile):
@@ -670,3 +670,55 @@ def test(self):
         # This used to fail
         c.run(f"create pkg {build_profile}")
         assert "protobuf/1.0 from local cache - Cache" in c.out
+
+    @pytest.mark.parametrize("host_version, assert_error, assert_msg", [
+        ("libgettext>", False, "gettext/0.2:5ab84d6acfe1f23c4fae0ab88f26e3a396351ac9 - Cache"),
+        # Error cases, just checking that we fail gracefully - no tracebacks
+        ("libgettext", True, "Package gettext has an invalid version number: '<host_version:libgettext'"),
+        (":>", True, "app/1.0 require ':': didn't find a matching host dependency"),
+        (">", True, "app/1.0 require '': didn't find a matching host dependency"),
+        (":", True, " Package gettext has an invalid version number: '<host_version::'"),
+        ("", True, " Package gettext has an invalid version number: '<host_version:'")
+    ])
+    def test_host_version_different_ref(self, host_version, assert_error, assert_msg):
+        tc = TestClient()
+        tc.save({"gettext/conanfile.py": GenConanfile("gettext"),
+                 "libgettext/conanfile.py": GenConanfile("libgettext"),
+                 "app/conanfile.py": GenConanfile("app", "1.0").with_requires("libgettext/[>0.1]")
+                .with_build_requires(f"gettext/<host_version:{host_version}")})
+        tc.run("create libgettext libgettext/0.2@")
+        tc.run("create gettext gettext/0.1@ --build-require")
+        tc.run("create gettext gettext/0.2@ --build-require")
+
+        tc.run("create app app/1.0@", assert_error=assert_error)
+        assert assert_msg in tc.out
+
+    @pytest.mark.parametrize("requires_tag,tool_requires_tag,fails", [
+        ("user/channel", "user/channel", False),
+        ("", "user/channel", True),
+        ("auser/achannel", "anotheruser/anotherchannel", True),
+    ])
+    def test_overriden_host_version_user_channel(self, requires_tag, tool_requires_tag, fails):
+        """
+        Make the tool_requires follow the regular require with the expression "<host_version>"
+        """
+        c = TestClient()
+        pkg = textwrap.dedent(f"""
+                from conan import ConanFile
+                class ProtoBuf(ConanFile):
+                    name = "pkg"
+                    version = "0.1"
+                    def requirements(self):
+                        self.requires("protobuf/1.0@{requires_tag}")
+                    def build_requirements(self):
+                        self.tool_requires("protobuf/<host_version>@{tool_requires_tag}")
+                """)
+        c.save({"protobuf/conanfile.py": GenConanfile("protobuf"),
+                "pkg/conanfile.py": pkg})
+        c.run(f"create protobuf 1.0@{requires_tag}")
+
+        c.run("create pkg", assert_error=fails)
+        if fails:
+            assert "pkg/0.1 require 'protobuf': didn't find a matching host dependency" in c.out
+        else:
+            assert "Package '08f50edefe03c3273e386557efc23dc41a9f600b' created" in c.out