diff --git a/src/main/java/com/google/devtools/build/lib/analysis/AspectResolver.java b/src/main/java/com/google/devtools/build/lib/analysis/AspectResolver.java
index 87a942d..d5e1f00 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/AspectResolver.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/AspectResolver.java
@@ -30,7 +30,6 @@
 import com.google.devtools.build.skyframe.SkyFunction;
 import com.google.devtools.build.skyframe.SkyKey;
 import com.google.devtools.build.skyframe.ValueOrException2;
-
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
@@ -52,7 +51,7 @@
       SkyFunction.Environment env,
       Map<SkyKey, ConfiguredTarget> configuredTargetMap,
       Iterable<Dependency> deps,
-      NestedSetBuilder<Package> transitivePackages)
+      @Nullable NestedSetBuilder<Package> transitivePackages)
       throws AspectFunction.AspectCreationException, InterruptedException {
     OrderedSetMultimap<Dependency, ConfiguredAspect> result = OrderedSetMultimap.create();
     Set<SkyKey> allAspectKeys = new HashSet<>();
@@ -97,7 +96,10 @@
         }
 
         result.put(dep, aspectValue.getConfiguredAspect());
-        transitivePackages.addTransitive(aspectValue.getTransitivePackages());
+        if (transitivePackages != null) {
+          transitivePackages.addTransitive(
+              aspectValue.getTransitivePackagesForPackageRootResolution());
+        }
       }
     }
     return result;
@@ -168,4 +170,4 @@
     }
     return dep.satisfies(aspect.getDefinition().getRequiredProviders());
   }
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/AspectFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/AspectFunction.java
index dab170e..adc0b34 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/AspectFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/AspectFunction.java
@@ -93,14 +93,23 @@
   private final BuildViewProvider buildViewProvider;
   private final RuleClassProvider ruleClassProvider;
   private final Supplier<Boolean> removeActionsAfterEvaluation;
+  /**
+   * Indicates whether the set of packages transitively loaded for a given {@link AspectValue} will
+   * be needed for package root resolution later in the build. If not, they are not collected and
+   * stored.
+   */
+  private final boolean storeTransitivePackagesForPackageRootResolution;
 
   AspectFunction(
       BuildViewProvider buildViewProvider,
       RuleClassProvider ruleClassProvider,
-      Supplier<Boolean> removeActionsAfterEvaluation) {
+      Supplier<Boolean> removeActionsAfterEvaluation,
+      boolean storeTransitivePackagesForPackageRootResolution) {
     this.buildViewProvider = buildViewProvider;
     this.ruleClassProvider = ruleClassProvider;
     this.removeActionsAfterEvaluation = Preconditions.checkNotNull(removeActionsAfterEvaluation);
+    this.storeTransitivePackagesForPackageRootResolution =
+        storeTransitivePackagesForPackageRootResolution;
   }
 
   /**
@@ -145,7 +154,6 @@
   public SkyValue compute(SkyKey skyKey, Environment env)
       throws AspectFunctionException, InterruptedException {
     SkyframeBuildView view = buildViewProvider.getSkyframeBuildView();
-    NestedSetBuilder<Package> transitivePackages = NestedSetBuilder.stableOrder();
     NestedSetBuilder<Label> transitiveRootCauses = NestedSetBuilder.stableOrder();
     AspectKey key = (AspectKey) skyKey.argument();
     ConfiguredAspectFactory aspectFactory;
@@ -259,6 +267,8 @@
     aspectPathBuilder.add(aspect);
 
     SkyframeDependencyResolver resolver = view.createDependencyResolver(env);
+    NestedSetBuilder<Package> transitivePackagesForPackageRootResolution =
+        storeTransitivePackagesForPackageRootResolution ? NestedSetBuilder.stableOrder() : null;
 
     // When getting the dependencies of this hybrid aspect+base target, use the aspect's
     // configuration. The configuration of the aspect will always be a superset of the target's
@@ -273,8 +283,12 @@
       // Get the configuration targets that trigger this rule's configurable attributes.
       ImmutableMap<Label, ConfigMatchingProvider> configConditions =
           ConfiguredTargetFunction.getConfigConditions(
-              target, env, resolver, originalTargetAndAspectConfiguration,
-              transitivePackages, transitiveRootCauses);
+              target,
+              env,
+              resolver,
+              originalTargetAndAspectConfiguration,
+              transitivePackagesForPackageRootResolution,
+              transitiveRootCauses);
       if (configConditions == null) {
         // Those targets haven't yet been resolved.
         return null;
@@ -312,7 +326,7 @@
                 toolchainContext,
                 ruleClassProvider,
                 view.getHostConfiguration(originalTargetAndAspectConfiguration.getConfiguration()),
-                transitivePackages,
+                transitivePackagesForPackageRootResolution,
                 transitiveRootCauses);
       } catch (ConfiguredTargetFunctionException e) {
         throw new AspectCreationException(e.getMessage());
@@ -337,7 +351,7 @@
           configConditions,
           toolchainContext,
           depValueMap,
-          transitivePackages);
+          transitivePackagesForPackageRootResolution);
     } catch (DependencyEvaluationException e) {
       if (e.getCause() instanceof ConfiguredValueCreationException) {
         ConfiguredValueCreationException cause = (ConfiguredValueCreationException) e.getCause();
@@ -434,10 +448,13 @@
       return null;
     }
 
-    NestedSet<Package> transitivePackages = NestedSetBuilder.<Package>stableOrder()
-        .addTransitive(real.getTransitivePackages())
-        .add(originalTarget.getPackage())
-        .build();
+    NestedSet<Package> transitivePackagesForPackageRootResolution =
+        storeTransitivePackagesForPackageRootResolution
+            ? NestedSetBuilder.<Package>stableOrder()
+                .addTransitive(real.getTransitivePackagesForPackageRootResolution())
+                .add(originalTarget.getPackage())
+                .build()
+            : null;
 
     return new AspectValue(
         originalKey,
@@ -447,7 +464,7 @@
         ConfiguredAspect.forAlias(real.getConfiguredAspect()),
         actionKeyContext,
         ImmutableList.of(),
-        transitivePackages,
+        transitivePackagesForPackageRootResolution,
         removeActionsAfterEvaluation.get());
   }
 
@@ -464,7 +481,7 @@
       ImmutableMap<Label, ConfigMatchingProvider> configConditions,
       ToolchainContext toolchainContext,
       OrderedSetMultimap<Attribute, ConfiguredTarget> directDeps,
-      NestedSetBuilder<Package> transitivePackages)
+      @Nullable NestedSetBuilder<Package> transitivePackagesForPackageRootResolution)
       throws AspectFunctionException, InterruptedException {
 
     SkyframeBuildView view = buildViewProvider.getSkyframeBuildView();
@@ -524,7 +541,9 @@
         configuredAspect,
         actionKeyContext,
         ImmutableList.copyOf(analysisEnvironment.getRegisteredActions()),
-        transitivePackages.build(),
+        transitivePackagesForPackageRootResolution == null
+            ? null
+            : transitivePackagesForPackageRootResolution.build(),
         removeActionsAfterEvaluation.get());
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/AspectValue.java b/src/main/java/com/google/devtools/build/lib/skyframe/AspectValue.java
index fb81622..a6ecc98 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/AspectValue.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/AspectValue.java
@@ -308,15 +308,15 @@
     }
   }
 
-
   // These variables are only non-final because they may be clear()ed to save memory. They are null
-  // only after they are cleared.
+  // only after they are cleared except for transitivePackagesForPackageRootResolution.
   @Nullable private Label label;
   @Nullable private Aspect aspect;
   @Nullable private Location location;
   @Nullable private AspectKey key;
   @Nullable private ConfiguredAspect configuredAspect;
-  @Nullable private NestedSet<Package> transitivePackages;
+  // May be null either after clearing or because transitive packages are not tracked.
+  @Nullable private NestedSet<Package> transitivePackagesForPackageRootResolution;
 
   public AspectValue(
       AspectKey key,
@@ -326,7 +326,7 @@
       ConfiguredAspect configuredAspect,
       ActionKeyContext actionKeyContext,
       List<ActionAnalysisMetadata> actions,
-      NestedSet<Package> transitivePackages,
+      NestedSet<Package> transitivePackagesForPackageRootResolution,
       boolean removeActionsAfterEvaluation) {
     super(actionKeyContext, actions, removeActionsAfterEvaluation);
     this.label = Preconditions.checkNotNull(label, actions);
@@ -334,7 +334,7 @@
     this.location = Preconditions.checkNotNull(location, label);
     this.key = Preconditions.checkNotNull(key, label);
     this.configuredAspect = Preconditions.checkNotNull(configuredAspect, label);
-    this.transitivePackages = Preconditions.checkNotNull(transitivePackages, label);
+    this.transitivePackagesForPackageRootResolution = transitivePackagesForPackageRootResolution;
   }
 
   public ConfiguredAspect getConfiguredAspect() {
@@ -363,7 +363,7 @@
     Preconditions.checkNotNull(location, this);
     Preconditions.checkNotNull(key, this);
     Preconditions.checkNotNull(configuredAspect, this);
-    Preconditions.checkNotNull(transitivePackages, this);
+    Preconditions.checkNotNull(transitivePackagesForPackageRootResolution, this);
     if (clearEverything) {
       label = null;
       aspect = null;
@@ -371,11 +371,17 @@
       key = null;
       configuredAspect = null;
     }
-    transitivePackages = null;
+    transitivePackagesForPackageRootResolution = null;
   }
 
-  public NestedSet<Package> getTransitivePackages() {
-    return Preconditions.checkNotNull(transitivePackages);
+  /**
+   * Returns the set of packages transitively loaded by this value. Must only be used for
+   * constructing the package -> source root map needed for some builds. If the caller has not
+   * specified that this map needs to be constructed (via the constructor argument in {@link
+   * AspectFunction#AspectFunction}), calling this will crash.
+   */
+  public NestedSet<Package> getTransitivePackagesForPackageRootResolution() {
+    return Preconditions.checkNotNull(transitivePackagesForPackageRootResolution);
   }
 
   // TODO(janakr): Add a nice toString after cl/150542180 is submitted.
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetFunction.java
index 8a34fdd..51584f2 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetFunction.java
@@ -112,23 +112,33 @@
   private final RuleClassProvider ruleClassProvider;
   private final Semaphore cpuBoundSemaphore;
   private final Supplier<Boolean> removeActionsAfterEvaluation;
+  /**
+   * Indicates whether the set of packages transitively loaded for a given {@link
+   * ConfiguredTargetValue} will be needed for package root resolution later in the build. If not,
+   * they are not collected and stored.
+   */
+  private final boolean storeTransitivePackagesForPackageRootResolution;
 
   ConfiguredTargetFunction(
       BuildViewProvider buildViewProvider,
       RuleClassProvider ruleClassProvider,
       Semaphore cpuBoundSemaphore,
-      Supplier<Boolean> removeActionsAfterEvaluation) {
+      Supplier<Boolean> removeActionsAfterEvaluation,
+      boolean storeTransitivePackagesForPackageRootResolution) {
     this.buildViewProvider = buildViewProvider;
     this.ruleClassProvider = ruleClassProvider;
     this.cpuBoundSemaphore = cpuBoundSemaphore;
     this.removeActionsAfterEvaluation = Preconditions.checkNotNull(removeActionsAfterEvaluation);
+    this.storeTransitivePackagesForPackageRootResolution =
+        storeTransitivePackagesForPackageRootResolution;
   }
 
   @Override
   public SkyValue compute(SkyKey key, Environment env) throws ConfiguredTargetFunctionException,
       InterruptedException {
     SkyframeBuildView view = buildViewProvider.getSkyframeBuildView();
-    NestedSetBuilder<Package> transitivePackages = NestedSetBuilder.stableOrder();
+    NestedSetBuilder<Package> transitivePackagesForPackageRootResolution =
+        storeTransitivePackagesForPackageRootResolution ? NestedSetBuilder.stableOrder() : null;
     NestedSetBuilder<Label> transitiveLoadingRootCauses = NestedSetBuilder.stableOrder();
     ConfiguredTargetKey configuredTargetKey = (ConfiguredTargetKey) key.argument();
     LabelAndConfiguration lc = LabelAndConfiguration.of(
@@ -155,7 +165,9 @@
     if (pkg.containsErrors()) {
       transitiveLoadingRootCauses.add(lc.getLabel());
     }
-    transitivePackages.add(pkg);
+    if (transitivePackagesForPackageRootResolution != null) {
+      transitivePackagesForPackageRootResolution.add(pkg);
+    }
     // TODO(bazel-team): This is problematic - we create the right key, but then end up with a value
     // that doesn't match; we can even have the same value multiple times. However, I think it's
     // only triggered in tests (i.e., in normal operation, the configuration passed in is already
@@ -187,9 +199,14 @@
     cpuBoundSemaphore.acquire();
     try {
       // Get the configuration targets that trigger this rule's configurable attributes.
-      ImmutableMap<Label, ConfigMatchingProvider> configConditions = getConfigConditions(
-          ctgValue.getTarget(), env, resolver, ctgValue, transitivePackages,
-          transitiveLoadingRootCauses);
+      ImmutableMap<Label, ConfigMatchingProvider> configConditions =
+          getConfigConditions(
+              ctgValue.getTarget(),
+              env,
+              resolver,
+              ctgValue,
+              transitivePackagesForPackageRootResolution,
+              transitiveLoadingRootCauses);
       if (env.valuesMissing()) {
         return null;
       }
@@ -231,7 +248,7 @@
               toolchainContext,
               ruleClassProvider,
               view.getHostConfiguration(configuration),
-              transitivePackages,
+              transitivePackagesForPackageRootResolution,
               transitiveLoadingRootCauses);
       if (env.valuesMissing()) {
         return null;
@@ -250,7 +267,7 @@
               depValueMap,
               configConditions,
               toolchainContext,
-              transitivePackages);
+              transitivePackagesForPackageRootResolution);
       return ans;
     } catch (DependencyEvaluationException e) {
       if (e.getCause() instanceof ConfiguredValueCreationException) {
@@ -350,7 +367,7 @@
       @Nullable ToolchainContext toolchainContext,
       RuleClassProvider ruleClassProvider,
       BuildConfiguration hostConfiguration,
-      NestedSetBuilder<Package> transitivePackages,
+      @Nullable NestedSetBuilder<Package> transitivePackagesForPackageRootResolution,
       NestedSetBuilder<Label> transitiveLoadingRootCauses)
       throws DependencyEvaluationException, ConfiguredTargetFunctionException,
           AspectCreationException, InterruptedException {
@@ -391,16 +408,20 @@
     }
 
     // Resolve configured target dependencies and handle errors.
-    Map<SkyKey, ConfiguredTarget> depValues = resolveConfiguredTargetDependencies(env,
-        depValueNames.values(), transitivePackages, transitiveLoadingRootCauses);
+    Map<SkyKey, ConfiguredTarget> depValues =
+        resolveConfiguredTargetDependencies(
+            env,
+            depValueNames.values(),
+            transitivePackagesForPackageRootResolution,
+            transitiveLoadingRootCauses);
     if (depValues == null) {
       return null;
     }
 
     // Resolve required aspects.
     OrderedSetMultimap<Dependency, ConfiguredAspect> depAspects =
-        AspectResolver.resolveAspectDependencies(env, depValues, depValueNames.values(),
-            transitivePackages);
+        AspectResolver.resolveAspectDependencies(
+            env, depValues, depValueNames.values(), transitivePackagesForPackageRootResolution);
     if (depAspects == null) {
       return null;
     }
@@ -430,7 +451,7 @@
       Environment env,
       SkyframeDependencyResolver resolver,
       TargetAndConfiguration ctgValue,
-      NestedSetBuilder<Package> transitivePackages,
+      @Nullable NestedSetBuilder<Package> transitivePackagesForPackageRootResolution,
       NestedSetBuilder<Label> transitiveLoadingRootCauses)
       throws DependencyEvaluationException, InterruptedException {
     if (!(target instanceof Rule)) {
@@ -477,8 +498,12 @@
     }
     configValueNames = staticConfigs.build();
 
-    Map<SkyKey, ConfiguredTarget> configValues = resolveConfiguredTargetDependencies(
-        env, configValueNames, transitivePackages, transitiveLoadingRootCauses);
+    Map<SkyKey, ConfiguredTarget> configValues =
+        resolveConfiguredTargetDependencies(
+            env,
+            configValueNames,
+            transitivePackagesForPackageRootResolution,
+            transitiveLoadingRootCauses);
     if (configValues == null) {
       return null;
     }
@@ -514,7 +539,7 @@
   private static Map<SkyKey, ConfiguredTarget> resolveConfiguredTargetDependencies(
       Environment env,
       Collection<Dependency> deps,
-      NestedSetBuilder<Package> transitivePackages,
+      @Nullable NestedSetBuilder<Package> transitivePackagesForPackageRootResolution,
       NestedSetBuilder<Label> transitiveLoadingRootCauses)
       throws DependencyEvaluationException, InterruptedException {
     boolean missedValues = env.valuesMissing();
@@ -533,7 +558,10 @@
           missedValues = true;
         } else {
           result.put(entry.getKey(), depValue.getConfiguredTarget());
-          transitivePackages.addTransitive(depValue.getTransitivePackages());
+          if (transitivePackagesForPackageRootResolution != null) {
+            transitivePackagesForPackageRootResolution.addTransitive(
+                depValue.getTransitivePackagesForPackageRootResolution());
+          }
         }
       } catch (ConfiguredValueCreationException e) {
         // TODO(ulfjack): If there is an analysis root cause, we drop all loading root causes.
@@ -569,7 +597,7 @@
       OrderedSetMultimap<Attribute, ConfiguredTarget> depValueMap,
       ImmutableMap<Label, ConfigMatchingProvider> configConditions,
       @Nullable ToolchainContext toolchainContext,
-      NestedSetBuilder<Package> transitivePackages)
+      @Nullable NestedSetBuilder<Package> transitivePackagesForPackageRootResolution)
       throws ConfiguredTargetFunctionException, InterruptedException {
     StoredEventHandler events = new StoredEventHandler();
     BuildConfiguration ownerConfig =
@@ -624,7 +652,9 @@
     return new ConfiguredTargetValue(
         configuredTarget,
         generatingActions,
-        transitivePackages.build(),
+        transitivePackagesForPackageRootResolution == null
+            ? null
+            : transitivePackagesForPackageRootResolution.build(),
         removeActionsAfterEvaluation.get());
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetValue.java b/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetValue.java
index 8cfee6a..a11e27a 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetValue.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetValue.java
@@ -38,20 +38,21 @@
 @VisibleForTesting
 public final class ConfiguredTargetValue extends ActionLookupValue {
 
-  // These variables are only non-final because they may be clear()ed to save memory. They are null
-  // only after they are cleared.
+  // These variables are only non-final because they may be clear()ed to save memory.
+  // configuredTarget is null only after it is cleared.
   @Nullable private ConfiguredTarget configuredTarget;
 
-  @Nullable private NestedSet<Package> transitivePackages;
+  // May be null either after clearing or because transitive packages are not tracked.
+  @Nullable private NestedSet<Package> transitivePackagesForPackageRootResolution;
 
   ConfiguredTargetValue(
       ConfiguredTarget configuredTarget,
       GeneratingActions generatingActions,
-      NestedSet<Package> transitivePackages,
+      @Nullable NestedSet<Package> transitivePackagesForPackageRootResolution,
       boolean removeActionsAfterEvaluation) {
     super(generatingActions, removeActionsAfterEvaluation);
     this.configuredTarget = Preconditions.checkNotNull(configuredTarget, generatingActions);
-    this.transitivePackages = Preconditions.checkNotNull(transitivePackages, generatingActions);
+    this.transitivePackagesForPackageRootResolution = transitivePackagesForPackageRootResolution;
   }
 
   @VisibleForTesting
@@ -66,8 +67,14 @@
     return actions;
   }
 
-  public NestedSet<Package> getTransitivePackages() {
-    return Preconditions.checkNotNull(transitivePackages);
+  /**
+   * Returns the set of packages transitively loaded by this value. Must only be used for
+   * constructing the package -> source root map needed for some builds. If the caller has not
+   * specified that this map needs to be constructed (via the constructor argument in {@link
+   * ConfiguredTargetFunction#ConfiguredTargetFunction}), calling this will crash.
+   */
+  public NestedSet<Package> getTransitivePackagesForPackageRootResolution() {
+    return Preconditions.checkNotNull(transitivePackagesForPackageRootResolution);
   }
 
   /**
@@ -79,16 +86,16 @@
    * called.
    *
    * @param clearEverything if true, clear the {@link #configuredTarget}. If not, only the {@link
-   *     #transitivePackages} field is cleared. Top-level targets need their {@link
-   *     #configuredTarget} preserved, so should pass false here.
+   *     #transitivePackagesForPackageRootResolution} field is cleared. Top-level targets need their
+   *     {@link #configuredTarget} preserved, so should pass false here.
    */
   public void clear(boolean clearEverything) {
     Preconditions.checkNotNull(configuredTarget);
-    Preconditions.checkNotNull(transitivePackages);
+    Preconditions.checkNotNull(transitivePackagesForPackageRootResolution);
     if (clearEverything) {
       configuredTarget = null;
     }
-    transitivePackages = null;
+    transitivePackagesForPackageRootResolution = null;
   }
 
   @VisibleForTesting
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeBuildView.java b/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeBuildView.java
index a1ba4e5..74c1cba 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeBuildView.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeBuildView.java
@@ -218,7 +218,9 @@
         skyframeExecutor.findArtifactConflicts();
 
     Collection<AspectValue> goodAspects = Lists.newArrayListWithCapacity(values.size());
-    NestedSetBuilder<Package> packages = NestedSetBuilder.stableOrder();
+    Path singleSourceRoot = skyframeExecutor.getForcedSingleSourceRootIfNoExecrootSymlinkCreation();
+    NestedSetBuilder<Package> packages =
+        singleSourceRoot == null ? NestedSetBuilder.stableOrder() : null;
     for (AspectValueKey aspectKey : aspectKeys) {
       AspectValue value = (AspectValue) result.get(aspectKey.getSkyKey());
       if (value == null) {
@@ -226,7 +228,9 @@
         continue;
       }
       goodAspects.add(value);
-      packages.addTransitive(value.getTransitivePackages());
+      if (packages != null) {
+        packages.addTransitive(value.getTransitivePackagesForPackageRootResolution());
+      }
     }
 
     // Filter out all CTs that have a bad action and convert to a list of configured targets. This
@@ -240,9 +244,10 @@
         continue;
       }
       goodCts.add(ctValue.getConfiguredTarget());
-      packages.addTransitive(ctValue.getTransitivePackages());
+      if (packages != null) {
+        packages.addTransitive(ctValue.getTransitivePackagesForPackageRootResolution());
+      }
     }
-    Path singleSourceRoot = skyframeExecutor.getForcedSingleSourceRootIfNoExecrootSymlinkCreation();
     PackageRoots packageRoots =
         singleSourceRoot == null
             ? new MapAsPackageRoots(
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutor.java b/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutor.java
index b23f49f..96fbd0b 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutor.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutor.java
@@ -415,11 +415,15 @@
             new BuildViewProvider(),
             ruleClassProvider,
             cpuBoundSemaphore,
-            removeActionsAfterEvaluation));
+            removeActionsAfterEvaluation,
+            shouldStoreTransitivePackagesInLoadingAndAnalysis()));
     map.put(
         SkyFunctions.ASPECT,
         new AspectFunction(
-            new BuildViewProvider(), ruleClassProvider, removeActionsAfterEvaluation));
+            new BuildViewProvider(),
+            ruleClassProvider,
+            removeActionsAfterEvaluation,
+            shouldStoreTransitivePackagesInLoadingAndAnalysis()));
     map.put(SkyFunctions.LOAD_SKYLARK_ASPECT, new ToplevelSkylarkAspectFunction());
     map.put(SkyFunctions.POST_CONFIGURED_TARGET,
         new PostConfiguredTargetFunction(new BuildViewProvider(), ruleClassProvider));
@@ -703,11 +707,22 @@
     return true;
   }
 
+  /**
+   * If not null, this is the only source root in the build, corresponding to the single element in
+   * a single-element package path. Such a single-source-root build need not plant the execroot
+   * symlink forest, and can trivially resolve source artifacts from exec paths. As a consequence,
+   * builds where this is not null do not need to track a package -> source root map, and so do not
+   * need to track all loaded packages.
+   */
   @Nullable
   protected Path getForcedSingleSourceRootIfNoExecrootSymlinkCreation() {
     return null;
   }
 
+  private boolean shouldStoreTransitivePackagesInLoadingAndAnalysis() {
+    return getForcedSingleSourceRootIfNoExecrootSymlinkCreation() == null;
+  }
+
   @VisibleForTesting
   protected abstract Injectable injectable();