Don't test for reference equality of the underlying IOException. It's overkill for these unit tests.

RELNOTES: None
PiperOrigin-RevId: 191122418

src/test/java/com/google/devtools/build/lib/skyframe/PackageFunctionTest.java

diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/PackageFunctionTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/PackageFunctionTest.java
index 07c7062..db71eda 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/PackageFunctionTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/PackageFunctionTest.java
@@ -696,7 +696,7 @@
     String errorMessage = errorInfo.getException().getMessage();
     assertThat(errorMessage).contains("nope");
     assertThat(errorInfo.getException()).isInstanceOf(NoSuchPackageException.class);
-    assertThat(errorInfo.getException()).hasCauseThat().isSameAs(exn);
+    assertThat(errorInfo.getException()).hasCauseThat().isInstanceOf(IOException.class);
   }
 
   @Test
@@ -714,7 +714,7 @@
     String errorMessage = errorInfo.getException().getMessage();
     assertThat(errorMessage).contains("nope");
     assertThat(errorInfo.getException()).isInstanceOf(NoSuchPackageException.class);
-    assertThat(errorInfo.getException()).hasCauseThat().isSameAs(exn);
+    assertThat(errorInfo.getException()).hasCauseThat().isInstanceOf(IOException.class);
   }
 
   private static class CustomInMemoryFs extends InMemoryFileSystem {