Make PackageLookupFunction hermetic. It was only non-hermetic because of deleted packages, and we can just aggressively delete the nodes in that case.

PiperOrigin-RevId: 228225515

src/main/java/com/google/devtools/build/lib/skyframe/SequencedSkyframeExecutor.java

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/SequencedSkyframeExecutor.java b/src/main/java/com/google/devtools/build/lib/skyframe/SequencedSkyframeExecutor.java
index 074f43f..e563a5a 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/SequencedSkyframeExecutor.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/SequencedSkyframeExecutor.java
@@ -17,6 +17,7 @@
 import com.google.common.base.Joiner;
 import com.google.common.base.Preconditions;
 import com.google.common.base.Predicate;
+import com.google.common.base.Predicates;
 import com.google.common.collect.Collections2;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -355,7 +356,7 @@
     for (PackageIdentifier deletedPackage : deletedPackages) {
       packagesToInvalidate.add(PackageLookupValue.key(deletedPackage));
     }
-    recordingDiffer.invalidate(packagesToInvalidate);
+    memoizingEvaluator.delete(Predicates.in(packagesToInvalidate));
   }
 
   /**

src/main/java/com/google/devtools/build/lib/skyframe/SkyFunctions.java

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/SkyFunctions.java b/src/main/java/com/google/devtools/build/lib/skyframe/SkyFunctions.java
index ae534ae..7673297 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/SkyFunctions.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/SkyFunctions.java
@@ -38,9 +38,10 @@
       SkyFunctionName.createHermetic("FILE_SYMLINK_INFINITE_EXPANSION_UNIQUENESS");
   public static final SkyFunctionName DIRECTORY_LISTING =
       SkyFunctionName.createHermetic("DIRECTORY_LISTING");
-  // Non-hermetic because unfortunately package lookups secretly access the set of deleted packages.
+  // Hermetic even though package lookups secretly access the set of deleted packages, becaused
+  // SequencedSkyframeExecutor deletes any affected PACKAGE_LOOKUP nodes when that set changes.
   public static final SkyFunctionName PACKAGE_LOOKUP =
-      SkyFunctionName.createNonHermetic("PACKAGE_LOOKUP");
+      SkyFunctionName.createHermetic("PACKAGE_LOOKUP");
   public static final SkyFunctionName CONTAINING_PACKAGE_LOOKUP =
       SkyFunctionName.createHermetic("CONTAINING_PACKAGE_LOOKUP");
   // Non-hermetic because accesses the package locator. Also does disk access.