fix skip binaries (#17033)

conans/client/graph/graph_binaries.py

@@ -447,7 +447,10 @@ def _skip_binaries(graph):
         required_nodes.add(graph.root)
         for node in graph.nodes:
             if node.binary in (BINARY_BUILD, BINARY_EDITABLE_BUILD, BINARY_EDITABLE):
-                if not node.build_allowed:  # Only those that are forced to build, not only "missing"
+                can_skip = node.conanfile.conf.get("tools.graph:skip_binaries",
+                                                   check_type=bool, default=True)
+                # Only those that are forced to build, not only "missing"
+                if not node.build_allowed or not can_skip:
                     required_nodes.add(node)
 
         root_nodes = required_nodes.copy()

test/integration/graph/test_skip_binaries.py

@@ -1,4 +1,5 @@
 import re
+import textwrap
 
 from conan.test.assets.genconanfile import GenConanfile
 from conan.test.utils.tools import TestClient, NO_SETTINGS_PACKAGE_ID
@@ -194,3 +195,43 @@ def test_skip_visible_build():
     c.run("create libc")
     c.run("install app --format=json")
     assert re.search(r"Skipped binaries(\s*)libb/0.1, liba/0.1", c.out)
+
+
+def test_skip_tool_requires_context():
+    c = TestClient()
+    cmake = textwrap.dedent("""
+        from conan import ConanFile
+        class CMake(ConanFile):
+            name = "cmake"
+            version = "1.0"
+            def package_info(self):
+                self.buildenv_info.define("MYVAR", "MYVALUE")
+            """)
+    gtest = textwrap.dedent("""
+        from conan import ConanFile
+        from conan.tools.files import load
+        class gtest(ConanFile):
+            name = "gtest"
+            version = "1.0"
+            settings = "os"
+            package_type = "static-library"
+            def build(self):
+                env = load(self, "conanbuildenv.sh")
+                self.output.info(f"MYENV: {env}")
+        """)
+    c.save({"cmake/conanfile.py": cmake,
+            "gtest/conanfile.py": gtest,
+            "lib/conanfile.py": GenConanfile("lib", "1.0").with_package_type("static-library")
+                                                          .with_test_requires("gtest/1.0"),
+            "app/conanfile.py": GenConanfile("app", "1.0").with_settings("os")
+                                                          .with_requires("lib/1.0"),
+            "profile": "[tool_requires]\ncmake/[>=1.0]"})
+
+    c.run("create cmake")
+    c.run("create gtest -s:a os=Linux")
+    c.run("create lib -s:a os=Linux")
+
+    c.run("remove gtest:* -c")
+    c.run("install app -s:a os=Linux -pr=profile -c=tools.graph:skip_binaries=False --build=missing")
+    assert 'export MYVAR="MYVALUE"' in c.out
+    assert "gtest/1.0: Package '9a4eb3c8701508aa9458b1a73d0633783ecc2270' built" in c.out