Attempt 1 at fixing bazelbuild#12553

src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java

@@ -54,6 +54,7 @@
 import com.google.devtools.build.lib.analysis.config.transitions.ConfigurationTransition;
 import com.google.devtools.build.lib.analysis.config.transitions.NoTransition;
 import com.google.devtools.build.lib.analysis.constraints.ConstraintSemantics;
+import com.google.devtools.build.lib.analysis.constraints.RuleContextConstraintSemantics;
 import com.google.devtools.build.lib.analysis.platform.ConstraintValueInfo;
 import com.google.devtools.build.lib.analysis.platform.PlatformInfo;
 import com.google.devtools.build.lib.analysis.stringtemplate.TemplateContext;
@@ -2292,6 +2293,13 @@ private boolean checkRuleDependencyMandatoryProviders(
         return true;
       }
 
+      if (RuleContextConstraintSemantics.prerequisiteIsIncompatible(prerequisite.getConfiguredTarget())) {
+        // If the prerequisite doesn't satisfy the required providers and it is incompatible (i.e.
+        // has an incompatible provider set), we pretend that the required providers are satisfied.
+        return true;
+      }
+
+      new Error().printStackTrace();
       unfulfilledRequirements.add(
           String.format(
               "'%s' does not have mandatory providers: %s",

src/main/java/com/google/devtools/build/lib/analysis/constraints/RuleContextConstraintSemantics.java

@@ -830,6 +830,15 @@ private static void addSelectValuesToSet(BuildType.Selector<?> select, final Set
     }
   }
 
+  public static boolean prerequisiteIsIncompatible(ConfiguredTarget prerequisite) {
+    if (prerequisite instanceof OutputFileConfiguredTarget) {
+      // For generated files, we want to query the generating rule for providers. genrule() for
+      // example doesn't attach providers like IncompatiblePlatformProvider to its outputs.
+      prerequisite = ((OutputFileConfiguredTarget) prerequisite).getGeneratingRule();
+    }
+    return prerequisite.getProvider(IncompatiblePlatformProvider.class) != null;
+  }
+
   /**
    * Creates an incompatible {@link ConfiguredTarget} if the corresponding rule is incompatible.
    *
@@ -873,22 +882,18 @@ public static ConfiguredTarget incompatibleConfiguredTarget(
     }
 
     // This is incompatible if one of the dependencies is as well.
-    ImmutableList.Builder<ConfiguredTarget> incompatibleDependenciesBuilder =
-        ImmutableList.builder();
-    for (ConfiguredTargetAndData infoCollection : prerequisiteMap.values()) {
-      ConfiguredTarget dependency = infoCollection.getConfiguredTarget();
-      if (dependency instanceof OutputFileConfiguredTarget) {
-        // For generated files, we want to query the generating rule for providers. genrule() for
-        // example doesn't attach providers like IncompatiblePlatformProvider to its outputs.
-        dependency = ((OutputFileConfiguredTarget) dependency).getGeneratingRule();
-      }
-      if (dependency.getProvider(IncompatiblePlatformProvider.class) != null) {
-        incompatibleDependenciesBuilder.add(dependency);
-      }
-    }
-
     ImmutableList<ConfiguredTarget> incompatibleDependencies =
-        incompatibleDependenciesBuilder.build();
+        stream(prerequisiteMap.values()).map(value -> value.getConfiguredTarget()).filter(dep -> prerequisiteIsIncompatible(dep)).collect(toImmutableList());
+    //ImmutableList.Builder<ConfiguredTarget> incompatibleDependenciesBuilder =
+    //    ImmutableList.builder();
+    //for (ConfiguredTargetAndData infoCollection : prerequisiteMap.values()) {
+    //  if (prerequisiteIsIncompatible(infoCollection.getConfiguredTarget())) {
+    //    incompatibleDependenciesBuilder.add(dependency);
+    //  }
+    //}
+
+    //ImmutableList<ConfiguredTarget> incompatibleDependencies =
+    //    incompatibleDependenciesBuilder.build();
     if (!incompatibleDependencies.isEmpty()) {
       return createIncompatibleConfiguredTarget(ruleContext, incompatibleDependencies, null);
     }

src/main/java/com/google/devtools/build/lib/analysis/constraints/TopLevelConstraintSemantics.java

@@ -187,6 +187,9 @@ private static String reportOnIncompatibility(ConfiguredTarget target) {
     while (target != null) {
       message += "\n    " + target.getLabel();
       provider = target.getProvider(IncompatiblePlatformProvider.class);
+      if (provider == null) {
+        System.out.println(message);
+      }
       ImmutableList<ConfiguredTarget> targetList = provider.targetsResponsibleForIncompatibility();
       if (targetList == null) {
         target = null;

src/test/shell/integration/target_compatible_with_test.sh

@@ -402,6 +402,49 @@ EOF
   expect_log 'FAILED: Build did NOT complete successfully'
 }
 
+function test_aaaaa() {
+  cat > target_skipping/rules.bzl <<EOF
+DummyProvider = provider()
+
+def _dummy_rule_impl(ctx):
+    return [DummyProvider()]
+
+dummy_rule = rule(
+    implementation = _dummy_rule_impl,
+    attrs = {
+        "deps": attr.label_list(providers=[DummyProvider]),
+    },
+)
+EOF
+
+  cat >> target_skipping/BUILD <<EOF
+load("//target_skipping:rules.bzl", "dummy_rule")
+
+dummy_rule(
+    name = "dummy1",
+    target_compatible_with = [
+        "//target_skipping:foo1",
+    ],
+)
+
+dummy_rule(
+    name = "dummy2",
+    deps = [
+        ":dummy1",
+    ],
+)
+EOF
+
+  cd target_skipping || fail "couldn't cd into workspace"
+
+  pwd >&2
+  bazel build \
+    --show_result=10 \
+    --host_platform=@//target_skipping:foo3_platform \
+    --platforms=@//target_skipping:foo3_platform \
+    //target_skipping/... &> "${TEST_log}" || fail "Bazel failed unexpectedly."
+}
+
 # Validates the same thing as test_non_top_level_skipping, but with a cc_test
 # and adding one more level of dependencies.
 function test_cc_test() {