[Pharo-users] Pharo 9 arbitrarily changes temporary variable names

Hi I define temporary variables in a method, e.g. |e r |, e.g. in a unit test, but when I run the test Pharo automatically replaces these with | tmp1 tmp2 |. A similar thing happens with method arguments.  For example methodName: aString at: anInteger will become methodName: arg1 at: arg2. This has happened through my entire model, not just as described above.  What is going on.  Is it a bug, or is there a setting that needs to be changed? Many thanks for any feedback on this. Regards Robert Briggs