Rakefile in instana-1.9.5 vs Rakefile in instana-1.9.6

@@ -8,37 +8,44 @@
 
   t.libs << "test"
   t.libs << "lib"
   t.test_files = FileList['test/**/*_test.rb']
 
-  case File.basename(ENV['BUNDLE_GEMFILE']).split('.').first
-  when /rails50/
-    t.test_files = [ 'test/frameworks/rails/activerecord5_test.rb',
-                     'test/frameworks/rails/actioncontroller_test.rb',
-                     'test/frameworks/rails/actionview5_test.rb' ]
-  when /rails42/
-    t.test_files = [ 'test/frameworks/rails/activerecord4_test.rb',
-                     'test/frameworks/rails/actioncontroller_test.rb',
-                     'test/frameworks/rails/actionview4_test.rb' ]
-  when /rails32/
-    t.test_files = [ 'test/frameworks/rails/activerecord3_test.rb',
-                     'test/frameworks/rails/actioncontroller_test.rb',
-                     'test/frameworks/rails/actionview3_test.rb' ]
-  when /libraries/
-    t.test_files = FileList['test/instrumentation/*_test.rb',
-                            'test/frameworks/cuba_test.rb',
-                            'test/frameworks/roda_test.rb',
-                            'test/frameworks/sinatra_test.rb']
+  if ENV.key?('BUNDLE_GEMFILE')
+    case File.basename(ENV['BUNDLE_GEMFILE']).split('.').first
+    when /rails50/
+      t.test_files = %w(test/frameworks/rails/activerecord5_test.rb
+                        test/frameworks/rails/actioncontroller_test.rb
+                        test/frameworks/rails/actionview5_test.rb)
+    when /rails42/
+      t.test_files = %w(test/frameworks/rails/activerecord4_test.rb
+                        test/frameworks/rails/actioncontroller_test.rb
+                        test/frameworks/rails/actionview4_test.rb)
+    when /rails32/
+      t.test_files = %w(test/frameworks/rails/activerecord3_test.rb
+                        test/frameworks/rails/actioncontroller_test.rb
+                        test/frameworks/rails/actionview3_test.rb)
+    when /libraries/
+      t.test_files = FileList['test/instrumentation/*_test.rb',
+                              'test/frameworks/cuba_test.rb',
+                              'test/frameworks/roda_test.rb',
+                              'test/frameworks/sinatra_test.rb']
+    else
+      t.test_files = FileList['test/agent/*_test.rb'] +
+                     FileList['test/tracing/*_test.rb'] +
+                     FileList['test/profiling/*_test.rb'] +
+                     FileList['test/benchmarks/bench_*.rb']
+    end
   else
     t.test_files = FileList['test/agent/*_test.rb'] +
-                   FileList['test/tracing/*_test.rb'] +
-                   FileList['test/profiling/*_test.rb'] +
-                   FileList['test/benchmarks/bench_*.rb']
+        FileList['test/tracing/*_test.rb'] +
+        FileList['test/profiling/*_test.rb'] +
+        FileList['test/benchmarks/bench_*.rb']
   end
 end
 
 task :environment do
-  ENV['INSTANA_GEM_DEV'] = 'true'
+  ENV['INSTANA_DEBUG'] = 'true'
   Bundler.require(:default, :development)
 end
 
 task :console => :environment do
   ARGV.clear