1 files changed, 6 insertions, 1 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/LtoBackendAction.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/LtoBackendAction.java
index d305317c6b..b53d38bbfd 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/LtoBackendAction.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/LtoBackendAction.java
@@ -22,6 +22,7 @@ import com.google.devtools.build.lib.actions.ActionExecutionContext;
 import com.google.devtools.build.lib.actions.ActionExecutionException;
 import com.google.devtools.build.lib.actions.ActionOwner;
 import com.google.devtools.build.lib.actions.Artifact;
+import com.google.devtools.build.lib.actions.CommandLineExpansionException;
 import com.google.devtools.build.lib.actions.ResourceSet;
 import com.google.devtools.build.lib.actions.RunfilesSupplier;
 import com.google.devtools.build.lib.analysis.actions.CommandLine;
@@ -169,7 +170,11 @@ public final class LtoBackendAction extends SpawnAction {
   protected String computeKey() {
     Fingerprint f = new Fingerprint();
     f.addString(GUID);
-    f.addStrings(getArguments());
+    try {
+      f.addStrings(getArguments());
+    } catch (CommandLineExpansionException e) {
+      throw new AssertionError("LtoBackendAction command line expansion cannot fail");
+    }
     f.addString(getMnemonic());
     f.addPaths(getRunfilesSupplier().getRunfilesDirs());
     ImmutableList<Artifact> runfilesManifests = getRunfilesSupplier().getManifests();