From an SL7 rolling machine:

/etc/cron.daily/0yum-daily.cron:

Update notice golang-github-coreos-go-systemd-0-0.4.git9d69345.el7 (from
sl-extras) is broken, or a bad duplicate, skipping.
You should report this problem to the owner of the sl-extras repository.
Update notice golang-github-godbus-dbus-0-0.1.gitcb98efb.el7 (from sl-extras)
is broken, or a bad duplicate, skipping.
Update notice golang-github-gorilla-context-0-0.22.git708054d.el7 (from
sl-extras) is broken, or a bad duplicate, skipping.
Update notice golang-github-kr-pty-0-0.19.git98c7b80.el7 (from sl-extras) is
broken, or a bad duplicate, skipping.
Update notice golang-github-syndtr-gocapability-0-0.5.git3454319.el7 (from
sl-extras) is broken, or a bad duplicate, skipping.
Update notice golang-googlecode-net-0-0.12.hg84a4013f96e0.el7 (from sl-extras)
is broken, or a bad duplicate, skipping.
Update notice golang-googlecode-sqlite-0-0.9.hg74691fb6f837.el7 (from
sl-extras) is broken, or a bad duplicate, skipping.

I saw this for a while in Fedora, can't find relevant bugs at the moment.

- Orion

-- 
Orion Poplawski
Technical Manager                     303-415-9701 x222
NWRA, Boulder/CoRA Office             FAX: 303-415-9702
3380 Mitchell Lane                       [log in to unmask]
Boulder, CO 80301                   http://www.nwra.com