Installing psycopg2 in virtual env on RHEL fails
Question: I have been on this for days now. Everytime I attempt to install psycopg2 into
a virtual environment on my RHEL VPS it fails with the following error. Anyone
with a clue should please help out. Thanks.

    
    
    (pyenv)[root@10 pyenv]# pip install psycopg2==2.5.4
     Collecting psycopg2==2.5.4
      Using cached psycopg2-2.5.4.tar.gz
      /tmp/pip-build-Vn6ET9/psycopg2/setup.py:12: DeprecationWarning: Parameters                                                                                                  to load are deprecated.  Call .resolve and .require separately.
      # FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
    Installing collected packages: psycopg2
    Running setup.py install for psycopg2
    building 'psycopg2._psycopg' extension
    gcc -pthread -fno-strict-aliasing -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=                                                                                         2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic                                                                                          -D_GNU_SOURCE -fPIC -fwrapv -DNDEBUG -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2                                                                                          -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic -                                                                                         D_GNU_SOURCE -fPIC -fwrapv -fPIC -DPSYCOPG_DEFAULT_PYDATETIME=1 -DPSYCOPG_VERSI                                                                                         ON="2.5.4 (dt dec pq3 ext)" -DPSYCOPG_EXTENSIONS=1 -DPSYCOPG_NEW_BOOLEAN=1 -DHA                                                                                         VE_PQFREEMEM=1 -DPG_VERSION_HEX=0x080414 -DPSYCOPG_EXTENSIONS=1 -DPSYCOPG_NEW_B                                                                                         OOLEAN=1 -DHAVE_PQFREEMEM=1 -I/usr/include/python2.6 -I. -I/usr/include -I/usr/                                                                                         include/pgsql/server -c psycopg/psycopgmodule.c -o build/temp.linux-x86_64-2.6/                                                                                         psycopg/psycopgmodule.o -Wdeclaration-after-statement
    unable to execute gcc: No such file or directory
    error: command 'gcc' failed with exit status 1
    Complete output from command /root/pyenv/bin/python -c "import setuptools,                                                                                          tokenize;__file__='/tmp/pip-build-Vn6ET9/psycopg2/setup.py';exec(compile(getatt                                                                                         r(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'ex                                                                                         ec'))" install --record /tmp/pip-9d8Iwo-record/install-record.txt --single-vers                                                                                         ion-externally-managed --compile --install-headers /root/pyenv/include/site/pyt                                                                                         hon2.6:
    running install
    
    running build
    
    running build_py
    
    creating build
    
    creating build/lib.linux-x86_64-2.6
    
    creating build/lib.linux-x86_64-2.6/psycopg2
    
    copying lib/psycopg1.py -> build/lib.linux-x86_64-2.6/psycopg2
    
    copying lib/extras.py -> build/lib.linux-x86_64-2.6/psycopg2
    
    copying lib/__init__.py -> build/lib.linux-x86_64-2.6/psycopg2
    
    copying lib/_json.py -> build/lib.linux-x86_64-2.6/psycopg2
    
    copying lib/pool.py -> build/lib.linux-x86_64-2.6/psycopg2
    
    copying lib/errorcodes.py -> build/lib.linux-x86_64-2.6/psycopg2
    
    copying lib/extensions.py -> build/lib.linux-x86_64-2.6/psycopg2
    
    copying lib/_range.py -> build/lib.linux-x86_64-2.6/psycopg2
    
    copying lib/tz.py -> build/lib.linux-x86_64-2.6/psycopg2
    
    creating build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/dbapi20_tpc.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/test_copy.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/test_notify.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/test_quote.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/dbapi20.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/test_lobject.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/test_bug_gc.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/test_psycopg2_dbapi20.py -> build/lib.linux-x86_64-2.6/psycop                                                                                         g2/tests
    
    copying tests/testutils.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/test_cursor.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/__init__.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/test_bugX000.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/test_types_basic.py -> build/lib.linux-x86_64-2.6/psycopg2/te                                                                                         sts
    
    copying tests/test_connection.py -> build/lib.linux-x86_64-2.6/psycopg2/tes                                                                                         ts
    
    copying tests/test_extras_dictcursor.py -> build/lib.linux-x86_64-2.6/psyco                                                                                         pg2/tests
    
    copying tests/test_transaction.py -> build/lib.linux-x86_64-2.6/psycopg2/te                                                                                         sts
    
    copying tests/test_module.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/test_dates.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/testconfig.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/test_cancel.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/test_async.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/test_with.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/test_green.py -> build/lib.linux-x86_64-2.6/psycopg2/tests
    
    copying tests/test_types_extras.py -> build/lib.linux-x86_64-2.6/psycopg2/t                                                                                         ests
    
    running build_ext
    
    building 'psycopg2._psycopg' extension
    
    creating build/temp.linux-x86_64-2.6
    
    creating build/temp.linux-x86_64-2.6/psycopg
    
    gcc -pthread -fno-strict-aliasing -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=                                                                                         2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic                                                                                          -D_GNU_SOURCE -fPIC -fwrapv -DNDEBUG -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2                                                                                          -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic -                                                                                         D_GNU_SOURCE -fPIC -fwrapv -fPIC -DPSYCOPG_DEFAULT_PYDATETIME=1 -DPSYCOPG_VERSI                                                                                         ON="2.5.4 (dt dec pq3 ext)" -DPSYCOPG_EXTENSIONS=1 -DPSYCOPG_NEW_BOOLEAN=1 -DHA                                                                                         VE_PQFREEMEM=1 -DPG_VERSION_HEX=0x080414 -DPSYCOPG_EXTENSIONS=1 -DPSYCOPG_NEW_B                                                                                         OOLEAN=1 -DHAVE_PQFREEMEM=1 -I/usr/include/python2.6 -I. -I/usr/include -I/usr/                                                                                         include/pgsql/server -c psycopg/psycopgmodule.c -o build/temp.linux-x86_64-2.6/                                                                                         psycopg/psycopgmodule.o -Wdeclaration-after-statement
    
    unable to execute gcc: No such file or directory
    
    error: command 'gcc' failed with exit status 1
    
    ----------------------------------------
    Command "/root/pyenv/bin/python -c "import setuptools, tokenize;__file__='/                                                                                         tmp/pip-build-Vn6ET9/psycopg2/setup.py';exec(compile(getattr(tokenize, 'open',                                                                                          open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --rec                                                                                         ord /tmp/pip-9d8Iwo-record/install-record.txt --single-version-externally-manag                                                                                         ed --compile --install-headers /root/pyenv/include/site/python2.6" failed with                                                                                          error code 1 in /tmp/pip-build-Vn6ET9/psycopg2
    


Answer: I found my way around it. I noticed it installs successfully globally. So I
installed psycopg2 globally and created a new virtual environment with
`--system-site-packages` option. Then I installed my other packages using the
`-I` option.

Hope this helps someone else.

OK. I later found out that I had no `gcc` installed. So I had to install it
first. And after that, I could `pip install psycopg2`. Thank you cel for the
direction.

