Backport to 1.2: Fix outside-of-project check when project path is not canonical.
Description
Backport of !832 (merged) to bst-1.2
This merge request, when approved, will close issue/bug: #673 (closed)
Backport of !832 (merged) to bst-1.2
This merge request, when approved, will close issue/bug: #673 (closed)