Go through the following steps to generate a debug log and store it in a file
called macvim.log. Be sure to type each command carefully or it will not work
(I suggest you copy and paste each line in order to avoid typos).
(The last step assumes that you have put MacVim in your /Applications
folder; adjust the last path if you have put it somewhere else. If you have
changed your shell then you may need to change the 2> to whatever command
is used to redirect to stderr with your shell.)
Interact with MacVim (e.g. do what you have to in order to recreate a bug)
and then quit (⌘Q). The debug log is now saved in a file called
macvim.log. Open it up and check that it is not empty (if it is the you
have most likely misspelled something in step 2, or forgot to quit MacVim).