It should be nice if existed a svn mailing list where we could be subscribed to follow any change in the code (I mean the diff)
I'm not sure that this is it, but on "Code" tab there is a mail envelope symbol. It this is not it, you should address this request to the sourceforge support team.
You seem to have CSS turned off.
Please don't fill out this field.
I did as you suggest and I'm waiting for a new commit to see if this works.
But I suspect that if this works, I'll get mail only on my sf account, which isn't what I'm expecting for.
You should create a mailing list named saying "gputils-svn", then follow instructions to add the hook script "svnnotify" to this list as described at https://sourceforge.net/apps/trac/sourceforge/wiki/Subversion%20hook%20scripts#svnnotify
This list have to be RO for most subscribers and RW for contributors who have a RW access on the svn.