[sdispater]

Pipenv sees the wrong constraint. It just aggregates the constraint for pbr that it sees.

In details:

oslo.utils==1.4.0 requires:

- pbr (>= 0.6, != 0.7, < 1.0) - oslo.i18n (>= 1.3)

So, poetry will take the latest version of oslo.i18n which requires:

- pbr (!= 2.1, >= 2.0)

Poetry will detect the conflict and backtrack oslo.i18n to version 2.1.0 which requires:

- pbr (>= 0.11, < 2.0)

This is compatible with the requirements of oslo.utils and pbr==0.11.1 will be installed