validate_build over settings

conans/client/conan_command_output.py

@@ -140,6 +140,10 @@ def _grab_info_data(self, deps_graph, grab_paths):
             item_data["build_id"] = build_id(conanfile)
             item_data["context"] = conanfile.context
 
+            item_data["invalid_build"] = node.cant_build is not False
+            if node.cant_build:
+                item_data["invalid_build_reason"] = node.cant_build
+
             python_requires = getattr(conanfile, "python_requires", None)
             if python_requires and not isinstance(python_requires, dict):  # no old python requires
                 item_data["python_requires"] = [repr(r)

conans/client/graph/graph.py

@@ -91,6 +91,8 @@ def __init__(self, ref, conanfile, context, recipe=None, path=None):
         self.id_direct_prefs = None
         self.id_indirect_prefs = None
 
+        self.cant_build = False  # It will set to a str with a reason if the validate_build() fails
+
     @property
     def id(self):
         return self._id

conans/client/graph/graph_binaries.py

@@ -48,7 +48,10 @@ def _evaluate_build(node, build_mode):
                     break
         if build_mode.forced(conanfile, ref, with_deps_to_build):
             conanfile.output.info('Forced build from source')
-            node.binary = BINARY_BUILD
+            if node.cant_build:
+                node.binary = BINARY_INVALID
+            else:
+                node.binary = BINARY_BUILD
             node.prev = None
             return True
 
@@ -178,7 +181,10 @@ def _evaluate_node(self, node, build_mode, update, remotes):
             pref = PackageReference(locked.ref, locked.package_id, locked.prev)  # Keep locked PREV
             self._process_node(node, pref, build_mode, update, remotes)
             if node.binary == BINARY_MISSING and build_mode.allowed(node.conanfile):
-                node.binary = BINARY_BUILD
+                if node.cant_build:
+                    node.binary = BINARY_INVALID
+                else:
+                    node.binary = BINARY_BUILD
             if node.binary == BINARY_BUILD:
                 locked.unlock_prev()
 
@@ -231,7 +237,10 @@ def _evaluate_node(self, node, build_mode, update, remotes):
                     if node.binary == BINARY_MISSING and node.package_id == PACKAGE_ID_INVALID:
                         node.binary = BINARY_INVALID
                 if node.binary == BINARY_MISSING and build_mode.allowed(node.conanfile):
-                    node.binary = BINARY_BUILD
+                    if node.cant_build:
+                        node.binary = BINARY_INVALID
+                    else:
+                        node.binary = BINARY_BUILD
 
             if locked:
                 # package_id was not locked, this means a base lockfile that is being completed
@@ -253,6 +262,8 @@ def _process_node(self, node, pref, build_mode, update, remotes):
             node.binary = BINARY_INVALID
             return
 
+
+
         if self._evaluate_build(node, build_mode):
             return
 
@@ -293,7 +304,10 @@ def _process_node(self, node, pref, build_mode, update, remotes):
                 local_recipe_hash = package_layout.recipe_manifest().summary_hash
                 if local_recipe_hash != recipe_hash:
                     conanfile.output.info("Outdated package!")
-                    node.binary = BINARY_BUILD
+                    if node.cant_build:
+                        node.binary = BINARY_INVALID
+                    else:
+                        node.binary = BINARY_BUILD
                     node.prev = None
                 else:
                     conanfile.output.info("Package is up to date")

conans/client/graph/graph_builder.py

@@ -3,7 +3,7 @@
 from conans.client.conanfile.configure import run_configure_method
 from conans.client.graph.graph import DepsGraph, Node, RECIPE_EDITABLE, CONTEXT_HOST, CONTEXT_BUILD
 from conans.errors import (ConanException, ConanExceptionInUserConanfileMethod,
-                           conanfile_exception_formatter)
+                           conanfile_exception_formatter, ConanInvalidConfiguration)
 from conans.model.conan_file import get_env_context_manager
 from conans.model.ref import ConanFileReference
 from conans.model.requires import Requirements, Requirement
@@ -471,4 +471,12 @@ def _create_new_node(self, current_node, dep_graph, requirement, check_updates,
 
         dep_graph.add_node(new_node)
         dep_graph.add_edge(current_node, new_node, requirement)
+
+        if hasattr(dep_conanfile, "validate_build") and callable(dep_conanfile.validate_build):
+            with conanfile_exception_formatter(str(dep_conanfile), "validate_build"):
+                try:
+                    dep_conanfile.validate_build()
+                except ConanInvalidConfiguration as e:
+                    new_node.cant_build = str(e)
+
         return new_node

conans/client/graph/graph_manager.py

@@ -9,7 +9,7 @@
 from conans.client.graph.graph_binaries import RECIPE_CONSUMER, RECIPE_VIRTUAL, BINARY_EDITABLE, \
     BINARY_UNKNOWN
 from conans.client.graph.graph_builder import DepsGraphBuilder
-from conans.errors import ConanException, conanfile_exception_formatter
+from conans.errors import ConanException, conanfile_exception_formatter, ConanInvalidConfiguration
 from conans.model.conan_file import get_env_context_manager
 from conans.model.graph_info import GraphInfo
 from conans.model.graph_lock import GraphLock, GraphLockFile
@@ -124,6 +124,7 @@ def load_graph(self, reference, create_reference, graph_info, build_mode, check_
         root_node = self._load_root_node(reference, create_reference, profile_host, graph_lock,
                                          root_ref, lockfile_node_id, is_build_require,
                                          require_overrides)
+
         deps_graph = self._resolve_graph(root_node, profile_host, profile_build, graph_lock,
                                          build_mode, check_updates, update, remotes, recorder,
                                          apply_build_requires=apply_build_requires)

conans/client/installer.py

@@ -423,7 +423,13 @@ def _build(self, nodes_by_level, keep_build, root_node, profile_host, profile_bu
         if invalid:
             msg = ["There are invalid packages (packages that cannot exist for this configuration):"]
             for node in invalid:
-                msg.append("{}: Invalid ID: {}".format(node.conanfile, node.conanfile.info.invalid))
+                if node.cant_build:
+                    msg.append("{}: Cannot build "
+                               "for this configuration: {}".format(node.conanfile,
+                                                                   node.cant_build))
+                else:
+                    msg.append("{}: Invalid ID: {}".format(node.conanfile,
+                                                           node.conanfile.info.invalid))
             raise ConanInvalidConfiguration("\n".join(msg))
         self._raise_missing(missing)
         processed_package_refs = {}

conans/test/integration/graph/test_validate_build.py

@@ -0,0 +1,54 @@
+import json
+import textwrap
+
+from conans.test.utils.tools import TestClient
+
+
+def test_basic_validate_build_test():
+
+    t = TestClient()
+    conanfile = textwrap.dedent("""
+    from conan import ConanFile
+    from conans.errors import ConanInvalidConfiguration
+
+    class myConan(ConanFile):
+        name = "foo"
+        version = "1.0"
+        settings = "os", "arch", "compiler"
+
+        def validate_build(self):
+            if self.settings.compiler == "gcc":
+                raise ConanInvalidConfiguration("This doesn't build in GCC")
+
+        def package_id(self):
+            del self.info.settings.compiler
+    """)
+
+    settings_gcc = "-s compiler=gcc -s compiler.libcxx=libstdc++11 -s compiler.version=11"
+    settings_clang = "-s compiler=clang -s compiler.libcxx=libc++ -s compiler.version=8"
+
+    t.save({"conanfile.py": conanfile})
+    t.run(f"create . {settings_gcc}", assert_error=True)
+
+    assert "foo/1.0: Cannot build for this configuration: This doesn't build in GCC" in t.out
+
+    t.run(f"create . {settings_clang}")
+
+    # Now with GCC again, but now we have the binary, we don't need to build, so it doesn't fail
+    t.run(f"create . {settings_gcc} --build missing")
+    assert "foo/1.0: Already installed!" in t.out
+
+    # But if I force the build... it will fail
+    t.run(f"create . {settings_gcc} ", assert_error=True)
+    assert "foo/1.0: Cannot build for this configuration: This doesn't build in GCC" in t.out
+
+    # What happens with a conan info?
+    t.run(f"info foo/1.0@ {settings_gcc} --json=myjson")
+    myjson = json.loads(t.load("myjson"))
+    assert myjson[0]["invalid_build"] is True
+    assert myjson[0]["invalid_build_reason"] == "This doesn't build in GCC"
+
+    t.run(f"info foo/1.0@ {settings_clang} --json=myjson")
+    myjson = json.loads(t.load("myjson"))
+    assert myjson[0]["invalid_build"] is False
+    assert "invalid_build_reason" not in myjson[0]