Don't warn about /dev/null having been modified

Fixes #4647

Closes #5003.

PiperOrigin-RevId: 192576694

1 files changed, 4 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/remote/RemoteSpawnCache.java b/src/main/java/com/google/devtools/build/lib/remote/RemoteSpawnCache.java
index b4b722a646..01cdabaca9 100644
--- a/src/main/java/com/google/devtools/build/lib/remote/RemoteSpawnCache.java
+++ b/src/main/java/com/google/devtools/build/lib/remote/RemoteSpawnCache.java
@@ -21,6 +21,7 @@ import com.google.devtools.build.lib.actions.SpawnResult;
 import com.google.devtools.build.lib.actions.SpawnResult.Status;
 import com.google.devtools.build.lib.actions.Spawns;
 import com.google.devtools.build.lib.actions.cache.Metadata;
+import com.google.devtools.build.lib.actions.cache.VirtualActionInput;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
 import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.events.Reporter;
@@ -197,6 +198,9 @@ final class RemoteSpawnCache implements SpawnCache {
 
         private void checkForConcurrentModifications() throws IOException {
           for (ActionInput input : inputMap.values()) {
+            if (input instanceof VirtualActionInput) {
+              continue;
+            }
             Metadata metadata = policy.getActionInputFileCache().getMetadata(input);
             if (metadata instanceof FileArtifactValue) {
               FileArtifactValue artifactValue = (FileArtifactValue) metadata;