I’ve just tried to user Emacs under Leopard for the first time since I upgraded my Tiger installation. I did the usual: opened up Terminal, typed ‘emacs’ and hit enter only to be presented with the following obscure error msg:

Fatal malloc_jumpstart() error

If you get this error, check the version of emacs you are using by issuing the following command:

emacs –version

On my machine, this was 21.2.1. The version of emacs that ships with Leopard is 22.1.1. To fix this error and make sure the Leopard is using the correct version, you first have to blast the emacs-i386 folder under /usr/bin. My advise is that you back it up:

sudo mv /usr/bin/emacs-i386 /usr/bin/emacs-i386.bak

Next, you have to rebuild the emacs-i386 by issuing the following command:

sudo /usr/libexec/dumpemacs -d

You will see a lot of text scroll back fairly quickly. After the command has completed, check the version of emacs again. This time around it should be 22.1.1 and you’re good to go!