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

Fixes #3428.

Change-Id: Ib3f45bc6856651cfb29d338d0b4480ba1dd77cea
PiperOrigin-RevId: 163760940

1 files changed, 6 insertions, 1 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/AspectFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/AspectFunction.java
index 234ed0bc9d..57b09e2490 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/AspectFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/AspectFunction.java
@@ -278,7 +278,12 @@ public final class AspectFunction implements SkyFunction {
         ImmutableList<Label> requiredToolchains = aspect.getDefinition().getRequiredToolchains();
         toolchainContext =
             ToolchainUtil.createToolchainContext(
-                env, requiredToolchains, key.getAspectConfiguration());
+                env,
+                String.format(
+                    "aspect %s applied to %s",
+                    aspect.getDescriptor().getDescription(), target.toString()),
+                requiredToolchains,
+                key.getAspectConfiguration());
       } catch (ToolchainContextException e) {
         // TODO(katre): better error handling
         throw new AspectCreationException(e.getMessage());