Don't crash when building environment groups directly

(following PackageGroup's precedent).

Also cleanup: generalize the pattern by which we determine
non-configurable target types.

--
MOS_MIGRATED_REVID=104125803

1 files changed, 5 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/packages/EnvironmentGroup.java b/src/main/java/com/google/devtools/build/lib/packages/EnvironmentGroup.java
index a5b977c3c8..0536dc3a68 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/EnvironmentGroup.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/EnvironmentGroup.java
@@ -310,6 +310,11 @@ public class EnvironmentGroup implements Target {
     return ConstantRuleVisibility.PRIVATE; // No rule should be referencing an environment_group.
   }
 
+  @Override
+  public boolean isConfigurable() {
+    return false;
+  }
+
   public static String targetKind() {
     return "environment group";
   }