During :vimgrep, each searched buffer triggers an asynchronous tag update, resulting in races for the tags file. Temporarily disable the automatic updates during this, through a global g:easytags_auto_disabled flag.
I just committed 6c7a66349ec7c1c92cb5f77afd44330189815d46 which implements the equivalent in the new feature branch, so I will close this pull request now. Thanks for the feedback!
During :vimgrep, each searched buffer triggers an asynchronous tag update, resulting in races for the tags file. Temporarily disable the automatic updates during this, through a global g:easytags_auto_disabled flag.