When using the -profile flag is it known behaviour that phobos unit tests fail?

[Gary Willoughby via Digitalmars-d]

When using the -profile flag is it known behaviour that phobos 
unit tests fail?

(Ubuntu 16.04 - DMD64 D Compiler v2.071.0)

For example, when following these steps I get a failed unit test:

$ cd /usr/include/dmd/phobos/std/
$ rdmd -I/usr/include/dmd/phobos/std 
-I/usr/include/dmd/phobos/core -main -unittest -profile format.d

Without the -profile flag it works.