pip3 install -r requirements.txt

gistfile1.txt

S:oneshot01 moxinni1$ pip3 install -r requirements.txt
Collecting alabaster==0.7.8 (from -r requirements.txt (line 1))
  Using cached alabaster-0.7.8-py2.py3-none-any.whl
Collecting alembic==0.9.1 (from -r requirements.txt (line 2))
  Using cached alembic-0.9.1.tar.gz
Collecting argcomplete==1.0.0 (from -r requirements.txt (line 4))
  Downloading argcomplete-1.0.0-py2.py3-none-any.whl
Collecting astropy==1.2.1 (from -r requirements.txt (line 5))
  Downloading astropy-1.2.1.tar.gz (8.2MB)
    100% |████████████████████████████████| 8.2MB 140kB/s
    Complete output from command python setup.py egg_info:
    running egg_info
    creating pip-egg-info/astropy.egg-info
    writing pip-egg-info/astropy.egg-info/PKG-INFO
    writing dependency_links to pip-egg-info/astropy.egg-info/dependency_links.txt
    writing entry points to pip-egg-info/astropy.egg-info/entry_points.txt
    writing requirements to pip-egg-info/astropy.egg-info/requires.txt
    writing top-level names to pip-egg-info/astropy.egg-info/top_level.txt
    writing manifest file 'pip-egg-info/astropy.egg-info/SOURCES.txt'
    warning: manifest_maker: standard file '-c' not found


    The C compiler used to compile Python gcc-4.2, and
    which is normally used to compile C extensions, is not
    available. You can explicitly specify which compiler to
    use by setting the CC environment variable, for example:

        CC=gcc python setup.py <command>

    or if you are using MacOS X, you can try:

        CC=clang python setup.py <command>


    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/57/n3pmt2vd73j7xyyd4dnqctgh0000gp/T/pip-build-1vof4aur/astropy/
S:oneshot01 moxinni1$