diff --git a/src/main/java/com/google/devtools/build/lib/bazel/repository/starlark/StarlarkBaseExternalContext.java b/src/main/java/com/google/devtools/build/lib/bazel/repository/starlark/StarlarkBaseExternalContext.java
index e1c5345..a876657 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/repository/starlark/StarlarkBaseExternalContext.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/repository/starlark/StarlarkBaseExternalContext.java
@@ -736,7 +736,7 @@
     } catch (IOException e) {
       throw new RepositoryFunctionException(
           new IOException(
-              "Couldn't delete temporary directory (" + downloadDirectory.getPathString() + ")", e),
+              "Couldn't delete temporary directory (" + downloadDirectory.getPathString() + "): " + e.getMessage(), e),
           Transience.TRANSIENT);
     }
     return downloadResult;