On 18 Oct 2016, at 10:17, Gregg Kellogg wrote:

Since updating to MacOS Sierra, I get this error when trying to open files from the shell. For example:

$ mate .

objc[48814]: Objective-C garbage collection is no longer supported.

Abort trap: 6

Does mate --version also fail? If not, what version does it report?

You should be able to force install of the latest by going to Preferences → Terminal and uninstall/install mate, but mate has never used Objective-C garbage collection, so I am rather puzzled about this error.

I’m running TextMate version 2.0-beta.12.4; trying to update says I have the latest version of TextMate.

This is the latest “regular release”, you’ll have to switch to nightly builds for something more recent, but we did not make any changes in mate for 10.12 compatibility (as it should work).