Debug prints for #28382

src/main/java/com/google/devtools/build/lib/actions/ActionInputMap.java

@@ -471,9 +471,9 @@ public String toString() {
     return MoreObjects.toStringHelper(this)
         .add("size", size)
         .add("all-files", sizeForDebugging())
-        .add("first-fifty-keys", Arrays.stream(keys).limit(50).collect(toList()))
-        .add("first-fifty-values", Arrays.stream(values).limit(50).collect(toList()))
-        .add("first-fifty-paths", Arrays.stream(paths).limit(50).collect(toList()))
+        .add("first-fifty-keys", Arrays.stream(keys).collect(toList()))
+        .add("first-fifty-values", Arrays.stream(values).collect(toList()))
+        .add("first-fifty-paths", Arrays.stream(paths).collect(toList()))
         .toString();
   }
 

src/main/java/com/google/devtools/build/lib/remote/RemoteSpawnRunner.java

@@ -604,8 +604,15 @@ private SpawnResult execLocallyAndUploadOrFail(
     // remotely, try to regenerate the lost inputs. This doesn't make sense for outputs of the
     // current action.
     if (reason == FailureReason.UPLOAD && cause instanceof BulkTransferException e) {
-      ImmutableMap<String, ActionInput> lostInputs =
-          e.getLostInputs(context.getInputMetadataProvider()::getInput);
+      ImmutableMap<String, ActionInput> lostInputs;
+      try {
+        lostInputs = e.getLostInputs(context.getInputMetadataProvider()::getInput);
+      } catch (RuntimeException re) {
+        System.err.printf(
+            "Action: %s%nSpawn: %s%nIMP: %s%n",
+            spawn.getResourceOwner(), spawn, context.getInputMetadataProvider());
+        throw re;
+      }
       if (!lostInputs.isEmpty()) {
         throw new LostInputsExecException(
             lostInputs, new ActionInputDepOwnerMap(lostInputs.values()));

src/main/java/com/google/devtools/build/lib/remote/common/BulkTransferException.java

@@ -89,8 +89,11 @@ public ImmutableMap<String, ActionInput> getLostInputs(
       var execPath = e.getExecPath();
       checkNotNull(execPath, "exec path not known for action input with digest %s", missingDigest);
       var actionInput = actionInputResolver.apply(execPath.getPathString());
-      checkNotNull(
-          actionInput, "ActionInput not found for filename %s in CacheNotFoundException", execPath);
+      if (actionInput == null) {
+        throw new IllegalStateException(
+            "ActionInput not found for filename %s in CacheNotFoundException".formatted(execPath),
+            this);
+      }
 
       lostInputs.put(DigestUtil.toString(missingDigest), actionInput);
     }

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

@@ -118,6 +118,7 @@ public ActionInput getInput(String execPath) {
   @Override
   public String toString() {
     return MoreObjects.toStringHelper(this)
+        .add("inputArtifactData", inputArtifactData)
         .add("inputArtifactDataSize", inputArtifactData.sizeForDebugging())
         .toString();
   }