For the SRCREV value you must to use "${AUTOREV}" during development to get the latest commit of the branch
ERROR: ... do_fetch: Fetcher failure: Unable to find revision ... in branch ... even from upstream
ERROR: ... do_fetch: Function failed: Fetcher failure for URL: 'git://...'. Unable to fetch URL from any source
ERROR: Logfile of failure stored in: ...
ERROR: Task 50 (XXX.bb, do_fetch) failed with exit code '1'
$ gedit XXX.bb
...
#SRCREV = "15668e96e3462bc76f29ee23e56cb7508a65afb9"
SRCREV = "${AUTOREV}"
...