Cache contexts for $access

gistfile1.diff

diff --git a/core/modules/block/src/BlockRepository.php b/core/modules/block/src/BlockRepository.php
index 485a66f..e2aa34e 100644
--- a/core/modules/block/src/BlockRepository.php
+++ b/core/modules/block/src/BlockRepository.php
@@ -77,9 +77,8 @@ public function getVisibleBlocksPerRegion(array $contexts) {
     foreach ($this->blockStorage->loadByProperties(array('theme' => $this->getTheme())) as $block_id => $block) {
       /** @var \Drupal\block\BlockInterface $block */
       // Set the contexts on the block before checking access.
-      if ($block->setContexts($contexts)->access('view')) {
-        $full[$block->getRegion()][$block_id] = $block;
-      }
+      $block->setContexts($contexts);
+      $full[$block->getRegion()][$block_id] = $block;
     }
 
     // Merge it with the actual values to maintain the region ordering.
diff --git a/core/modules/block/src/Plugin/DisplayVariant/BlockPageVariant.php b/core/modules/block/src/Plugin/DisplayVariant/BlockPageVariant.php
index 7b67093..d8b7635 100644
--- a/core/modules/block/src/Plugin/DisplayVariant/BlockPageVariant.php
+++ b/core/modules/block/src/Plugin/DisplayVariant/BlockPageVariant.php
@@ -12,6 +12,7 @@
 use Drupal\block\Event\BlockEvents;
 use Drupal\Core\Block\MainContentBlockPluginInterface;
 use Drupal\Core\Block\MessagesBlockPluginInterface;
+use Drupal\Core\Cache\CacheableMetadata;
 use Drupal\Core\Display\PageVariantInterface;
 use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\Core\Entity\EntityViewBuilderInterface;
@@ -133,6 +134,14 @@ public function build() {
     foreach ($this->blockRepository->getVisibleBlocksPerRegion($contexts) as $region => $blocks) {
       /** @var $blocks \Drupal\block\BlockInterface[] */
       foreach ($blocks as $key => $block) {
+        $access = $block->access('view', NULL, TRUE);
+        if ($access->isForbidden()) {
+          $build[$region][$key] = [];
+          CacheableMetadata::createFromObject($access)
+            ->applyTo($build[$region][$key]);
+
+          continue;
+        }
         $block_plugin = $block->getPlugin();
         if ($block_plugin instanceof MainContentBlockPluginInterface) {
           $block_plugin->setMainContent($this->mainContent);