llvm dev - Apr 2016 - error: unable to rename temporary

When compiling using clang this happens about 2 times out of 1000:

error: unable to rename temporary '/tmp/rand000732-e14426.o-bc7be374' to
output file '/tmp/rand000732-e14426.o': 'No such file or
directory'

Anyone else run into this? I'm not sure how to debug it.

I see this primarily during Csmith testing. It never happens to GCC, 
only LLVM.  So either we have some kind of funny low-grade 
nondeterministic bug in the file manipulation code or else Linux does.

Machine is running Ubuntu 14.04 and is otherwise rock solid. This is 
ext4 on an SSD. There's no NFS or anything like that. Disk is far from full.

John