rspreadsheet.gemspec in rspreadsheet-0.2.15 vs rspreadsheet.gemspec in rspreadsheet-0.3

@@ -16,12 +16,18 @@
   spec.files         = `git ls-files -z`.split("\x0")
   spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ["lib"]
 
+  def self.package_installed?(pkgname)
+    system("dpkg-query -l #{pkgname} | grep -q '^i'")
+  end
+  
   # runtime dependencies
-  spec.add_runtime_dependency 'libxml-ruby', '~>2.7'   # parsing XML files
+  unless package_installed?('ruby-libxml')
+    spec.add_runtime_dependency 'libxml-ruby', '~>2.7'   # parsing XML files
+  end
   spec.add_runtime_dependency 'rubyzip', '~>1.1'       # opening zip files
   spec.add_runtime_dependency 'andand', '~>1.3'
 
   # development dependencies
   spec.add_development_dependency "bundler", "~> 1.5"
@@ -30,10 +36,16 @@
   spec.add_development_dependency "rspec", '~>2'       # testing
   spec.add_development_dependency 'pry-nav', '~>0'     # enables pry 'next', 'step' commands
 
   # optional and testing
   spec.add_development_dependency "coveralls", '~>0.7'
-  spec.add_development_dependency "guard", '~>2.6'
-  spec.add_development_dependency "guard-rspec", '~>2.6'
+
+  if RUBY_VERSION.split('.')[0] !=  "1"
+    # ruby_dep starts to require ruby 2.2.5 which raises errors with ruby 1.9.3
+#     spec.add_development_dependency "guard", '~>2.13'
+#     spec.add_development_dependency "guard-rspec", '~>4.6'
+  end
+  
 #   spec.add_development_dependency 'equivalent-xml'     # implementing xml diff
 
 end
+