Improve error message when requesting an invalid toolchain type from the context.

Fixes #3428.

Change-Id: Ib3f45bc6856651cfb29d338d0b4480ba1dd77cea
PiperOrigin-RevId: 163760940

1 files changed, 4 insertions, 3 deletions

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 4e3356d052..1b783b9926 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
@@ -234,10 +234,11 @@ public final class ConfiguredTargetFunction implements SkyFunction {
       // Determine what toolchains are needed by this target.
       ToolchainContext toolchainContext = null;
       if (target instanceof Rule) {
-        ImmutableList<Label> requiredToolchains =
-            ((Rule) target).getRuleClassObject().getRequiredToolchains();
+        Rule rule = ((Rule) target);
+        ImmutableList<Label> requiredToolchains = rule.getRuleClassObject().getRequiredToolchains();
         toolchainContext =
-            ToolchainUtil.createToolchainContext(env, requiredToolchains, configuration);
+            ToolchainUtil.createToolchainContext(
+                env, rule.toString(), requiredToolchains, configuration);
         if (env.valuesMissing()) {
           return null;
         }