It would be nice if callgrind reports could include a special line, in the form of a comment that specifies the git hash, if applicable, of the application being run. That feature would only work if the binary executed by callgrind is located in a git repository and would consist into adding # git revision: <git-hash> in the report. That feature would be usefull when the user keeps several reports in his git repository but does not remind exactly which one matches to a given revision.