We've seen this a few times (e.g.,
http://www.open-mpi.org/community/lists/users/2015/06/27057.php
reported via @siegmargross). I'm not entirely sure why it happens --
the best I can come up with is a poorly-synchronized network
filesystem and/or a bug in "make". For example: this code hasn't
changed in forever, and it only happens to users *sometimes*.
Regardless, avoid the error altogether by removing the file before
making the sym link (it should be a sym link anyway -- if there's
something there, it should be safe to remove it before we re-create
the sym link that should be there in the first place).
(cherry picked from commit 0edd265ea045e649c9489e3cb8fdb657800d95c3)
fbaf6888f8