@conninfo is not always defined in a describe context

So define the constants in a before block.

spec/pg/gc_compact_spec.rb

@@ -5,31 +5,33 @@
 
 if GC.respond_to?(:compact)
 	describe "GC.compact" do
-		TM1 = Class.new(PG::TypeMapByClass) do
-			def conv_array(value)
-				PG::TextEncoder::JSON.new
-			end
-		end.new
-		TM1[Array] = :conv_array
+		before :all do
+			TM1 = Class.new(PG::TypeMapByClass) do
+				def conv_array(value)
+					PG::TextEncoder::JSON.new
+				end
+			end.new
+			TM1[Array] = :conv_array
 
-		E1 = PG::TextEncoder::JSON.new
+			E1 = PG::TextEncoder::JSON.new
 
-		TM2 = PG::TypeMapByClass.new
-		TM2.default_type_map = PG::TypeMapInRuby.new
+			TM2 = PG::TypeMapByClass.new
+			TM2.default_type_map = PG::TypeMapInRuby.new
 
-		TMBC = PG::TypeMapByColumn.new([PG::TextDecoder::Float.new])
+			TMBC = PG::TypeMapByColumn.new([PG::TextDecoder::Float.new])
 
 
-		CONN2 = PG.connect(@conninfo)
-		CONN2.type_map_for_results = PG::BasicTypeMapForResults.new(CONN2)
+			CONN2 = PG.connect(@conninfo)
+			CONN2.type_map_for_results = PG::BasicTypeMapForResults.new(CONN2)
 
-		RES1 = CONN2.exec("SELECT 234")
+			RES1 = CONN2.exec("SELECT 234")
 
-		TUP1 = RES1.tuple(0)
+			TUP1 = RES1.tuple(0)
 
-		TM3 = PG::TypeMapByClass.new
-		CPYENC = PG::TextEncoder::CopyRow.new type_map: TM3
-		RECENC = PG::TextEncoder::Record.new type_map: TM3
+			TM3 = PG::TypeMapByClass.new
+			CPYENC = PG::TextEncoder::CopyRow.new type_map: TM3
+			RECENC = PG::TextEncoder::Record.new type_map: TM3
+		end
 
 		# Use GC.verify_compaction_references instead of GC.compact .
 		# This has the advantage that all movable objects are actually moved.