The latest stable version of Mu is here!

Version 1.0.3 is a bug-fix release with no new features.

We didn’t intend to cut this release but changes in the way the latest OSX works meant that code highlighting didn’t work correctly. We also managed to apply a fix to an annoying bug relating to where Mu set the current working directory for scripts run in Python3 mode.

OSX Catalina has posed a number of problems, from the incorrect rendering mentioned above, to the way the application should be installed and problems with permissions when flashing a BBC micro:bit.

The simple answer to the installation story is, once you’ve installed Mu in your Applications folder, you should first open it with CTRL-click (not a double click) and select the “Open” button in the resulting pop-up. Subsequent runs of Mu can be started in the usual “double click” way. If you don’t do the “CTRL-click” trick you’ll see a pop-up complaining about Mu not being checked for malicious software.

Because OSX Catalina also interferes with disk access permissions that relate to the BBC micro:bit, then flashing won’t work unless you run Mu as an administrator with the following commands in the terminal (you may also need to supply your password too):

$ cd /Applications
$ sudo open

If you spot any bugs, please don’t hesitate to let us know.

Once again, many thanks to all the people in our community who have made such important and helpful contributions: Tim Golden for the bug fix for setting the current working directory and the many folks who reported and helped triage and fix the OSX related problems.

Please accept our apologies for not releasing a fix sooner. In our defence, Mu is a volunteer led project and sometimes it takes a while to find the time and space to triage problems, updates things, cut a release and announce it.

Finally, if you find Mu useful or would like to support the goals of this project, you might want to think about sponsoring the creator and lead maintainer Nicholas Tollervey.