Error code 1 on installation

[Lorenz25]

I've tried installing via Pip 1.9 in a virtualenvironment with Python 3.5 and got this:
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-7sivpd88/psycopg2/
I could get around this one by replacing psycopg 2.6 with 2.7, but I still get the same error for rjsmin and rcssmin. Deleting them from requirements.txt didn't help, rcssmin is a dependency of some other modul.
The full output of the latter is:
Command "/home/lorenz/.virtualenvs/wagtdemo/bin/python3 -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-oj1jge4b/rcssmin/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /tmp/pip-_tba2y_o-record/install-record.txt --single-version-externally-managed --compile --install-headers /home/lorenz/.virtualenvs/wagtdemo/include/site/python3.5/rcssmin" failed with error code 1 in /tmp/pip-build-oj1jge4b/rcssmin/