This is happening to me too.
- Bug#896644: openmpi-bin: postinst script fails Boyuan Yang
- Bug#896644: Indeed not fixed in 3.0.1-7 Diederik de Haas
- Bug#896644: postinst failure Aaron Schrab
- Bug#896644: openmpi-bin: postinst script fails Jan Christoph Uhde
- Bug#896644: (no subject) Kyle Edwards
- Bug#896644: Looks like it is fixed in 3.0.1-8 Diederik de Haas