Adding files to the global gitignore (usually) doesn’t trigger the automatic refresh, but it should.

Setup

1. In SourceTree, make sure “Refresh automatically when files change” is checked. Confirm this:

   1. ~/ $ mkdir demoIgnoreGlobal
      ~/ $ cd demoIgnoreGlobal/
      demoIgnoreGlobal/ $ git init
      Initialized empty Git repository in ~/demoIgnoreGlobal/.git/

   2. Open ~/demoIgnoreGlobal in SourceTree. SourceTree correctly displays it as an empty repository.

   3. demoIgnoreGlobal/ $ touch theBaz

      SourceTree will detect this file and automatically refresh (it may take a second or two), showing theBaz as unstaged.

   4. Confirm that command-line git sees the file:

      demoIgnoreGlobal/ $ git status
      On branch master
      
      Initial commit
      
      Untracked files:
        (use "git add <file>..." to include in what will be committed)
      
      	theBaz
      
      nothing added to commit but untracked files present (use "git add" to track)

   5. demoIgnoreGlobal/ $ echo theBaz > .gitignore

      SourceTree will detect this change, correctly showing .gitignore as unstaged and hiding theBaz.

   6. Now that we’ve confirmed that the auto-refresh does work, remove the local .gitignore.

      demoIgnoreGlobal/ $ rm .gitignore

      SourceTree correctly shows theBaz as unstaged once again.

2. Confirm that the global .gitignore is set up correctly.

   1. demoIgnoreGlobal/ $ git config --get core.excludesFile
      /Users/<username redacted>/.gitignore_global

   2. Open the SourceTree preferences pane, switch to the Git tab, and confirm that the path in the dialog matches the result of that command.

Test

1. demoIgnoreGlobal/ $ echo theBaz >> ~/.gitignore_global

   Watch SourceTree for a while. Most of the time, theBaz will not disappear. (It happened to me once, but I think I must have clicked something that triggered a refresh.)

2. Click the file listing for theBaz. Double-click theBaz to have SourceTree open the file. SourceTree doesn’t refresh.
3. Confirm that command-line git no longer sees the file:

   demoIgnoreGlobal/ $ git status
   On branch master
   
   Initial commit
   
   nothing to commit (create/copy files and use "git add" to track)

Environment

SourceTree-Beta Version 2.5.2 (109) (per the About dialog)