poudriere failures after pkg 1.9.0 update

[Stefan Ehmann]

In my poudriere run from today nearly all packages failed.
pkg was upgraded to 1.9.0 since the last run,

Here are the relevant lines from 3 different build logs:

[10amd64-default-job-01] `-- Extracting python27-2.7.12: ......
pkg-static: Fail to create temporary file:
/usr/local/lib/python2.7/test/decimaltestdata/.or.decTest.0zPFOC6i4BVl:
File exists

[10amd64-default-job-01] |   | `-- Extracting libX11-1.6.4,1: ...
pkg-static: Fail to create temporary file:
/usr/local/man/man3/.XDrawString16.3.gz.zeXVDUi2eY7z: File exists

[10amd64-default-job-01] Extracting ruby-2.2.5_1,1: ..
pkg-static: Fail to create temporary file:
/usr/local/share/ri/2.2/system/Fixnum/.inspect-i.ri.J96xApHkdlnr: File
exists