Problems installing pfs_utils package

(This is almost a verbatim copy of an email I sent to Craig and Robert some time ago; at that time I couldn't open issues on JIRA. Please excuse me if I'm filing this in the wrong category ... I'm not yet completely familiar with the internal organization...)

The packages ets_fiberalloc and ets_shuffle are going to depend on pfs_utils for coordinate conversions in the future. In preparation for that I tried to install the package locally. This requires scons, which was not a problem to install.
It also depends in lsst.sconsUtils, which I cloned from Github. Here the trouble started. The "scons" command for lsst.sconsUtils insists on calling "pytest" (hardwired), which is called "pytest-3" on my machine. I managed to adjust this, but now I get

running global pytest...
ERROR: usage: pytest-3 [options] [file_or_dir] [file_or_dir] [...]
pytest-3: error: unrecognized arguments:
--session2file=tests/.tests/pytest-sconsUtils.xml.out
 inifile: None
 rootdir: /home/martin/codes/sconsUtils

Do you have any advice how to proceed?