CHANGES.md in pycall-1.2.1 vs CHANGES.md in pycall-1.3.0.dev

@@ -1,6 +1,10 @@
 # The change history of PyCall
 
+## master
+
+* Add `PyCall.without_gvl` for explicitly releasing the RubyVM GVL
+
 ## 1.2.1
 
 * Prevent circular require in pycall/iruby.rb
 
 ## 1.2.0