Develop Reference

/usr/bin/ld: cannot find -lffi while installing cffi 1.11.5 package

enter code hereI'm trying to install paramiko module in my linux server. The pip is blocked on the server, So i am manually copying the package zips and installing them from setup.py
when i try installing paramiko i get
error: Could not find suitable distribution for Requirement.parse('pynacl>=1.0.1')
so i download the PyNaCl package, but i get
distutils.errors.DistutilsError: Could not find suitable distribution for Requirement.parse('cffi>=1.1.0')
pynacl needs cffi 1.1.0 above:
so while installing cffi1.11.5 i get the below error:
[root#homecffi-1.11.5]# python3.5 setup.py install
running install
---
---
installing library code to build/bdist.linux-x86_64/egg
--
--
building '_cffi_backend' extension
gcc -pthread -fno-strict-aliasing -Wsign-compare -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -fPIC -DUSE__THREAD -DHAVE_SYNC_SYNCHRONIZE -I/usr/local/lib/libffi-3.1/include -I/usr/local/include/python3.5m -c c/_cffi_backend.c -o build/temp.linux-x86_64-3.5/c/_cffi_backend.o
c/_cffi_backend.c: In function ‘b_callback’:
c/_cffi_backend.c:5911: warning: ‘ffi_prep_closure’ is deprecated (declared at /usr/local/include/ffi.h:341)
gcc -pthread -shared build/temp.linux-x86_64-3.5/c/_cffi_backend.o -L$(libdir)/../lib64 -lffi -o build/lib.linux-x86_64-3.5/_cffi_backend.cpython-35m-x86_64-linux-gnu.so
/usr/bin/ld: cannot find -lffi
collect2: ld returned 1 exit status
error: command 'gcc' failed with exit status 1
Can anyone help me with this?

If this is a Debian or Ubuntu machine,
sudo apt install libffi-dev
and then try again.
For other distributions, the installation method and package name may be different.

pip install pubnub throws 'gcc' failed error

I am trying to install pubnub libraries and I get the error when I do pip install pubnub
Compiling support for Intel AES instructions
building 'Crypto.Hash._MD2' extension
creating build/temp.linux-x86_64-2.7
creating build/temp.linux-x86_64-2.7/src
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 -DLTC_NO_ASM -DHAVE_CPUID_H -Isrc/ -I/usr/include/python2.7 -c src/MD2.c -o build/temp.linux-x86_64-2.7/src/MD2.o
gcc -pthread -shared build/temp.linux-x86_64-2.7/src/MD2.o -L/usr/lib64 -lpython2.7 -o build/lib.linux-x86_64-2.7/Crypto/Hash/_MD2.so
/usr/bin/ld: cannot find -lpython2.7
collect2: error: ld returned 1 exit status
error: command 'gcc' failed with exit status 1
These are the steps I followed
curl -O https://bootstrap.pypa.io/get-pip.py
sudo python27 get-pip.py
sudo yum install git
git clone https://github.com/pubnub/python && cd python/python
sudo update-alternatives --config python
sudo yum install python-devel
sudo yum install gcc
Thanks

You need to install Python's header files. How you do that will depend on your operating system.
On Debian or Ubuntu, for example, something like
sudo apt-get install python-dev
should do it.
On Fedora / CentOS / Red Hat, try
sudo yum install python-devel

The solution for this, I had to follow these steps
ld -lpython2.7 --verbose
attempt to open /usr/x86_64-amazon-linux/lib64/libpython2.7.so failed
attempt to open /usr/x86_64-amazon-linux/lib64/libpython2.7.a failed
attempt to open /usr/local/lib64/libpython2.7.so failed
attempt to open /usr/local/lib64/libpython2.7.a failed
attempt to open /lib64/libpython2.7.so failed
attempt to open /lib64/libpython2.7.a failed
attempt to open /usr/lib64/libpython2.7.so failed
attempt to open /usr/lib64/libpython2.7.a failed
attempt to open /usr/x86_64-amazon-linux/lib/libpython2.7.so failed
attempt to open /usr/x86_64-amazon-linux/lib/libpython2.7.a failed
attempt to open /usr/lib64/libpython2.7.so failed
attempt to open /usr/lib64/libpython2.7.a failed
attempt to open /usr/local/lib/libpython2.7.so failed
attempt to open /usr/local/lib/libpython2.7.a failed
attempt to open /lib/libpython2.7.so failed
attempt to open /lib/libpython2.7.a failed
attempt to open /usr/lib/libpython2.7.so failed
attempt to open /usr/lib/libpython2.7.a failed
Check ldconfig softlink for python and find out what its pointing to
ldconfig -p | grep python2.7
libpython2.7.so.1.0 (libc6,x86-64) => /usr/lib64/libpython2.7.so.1.0
This shows that it was looking for a wrong softlink and I changed the soft link like this
sudo ln -s /usr/lib64/libpython2.7.so.1.0 /usr/lib64/libpython2.7.so
and then had to run pip like this
sudo /usr/local/bin/pip install pubnub -- Location of pip installed
Worked Pretty Good

installing cx_freeze on ubuntu

i have kubuntu 15.10 with python2.7 and python 3.4m installed
if i install cxfreeze with sudo apt-get cx_freeze it is installed with no issues but the problem is when i compile my python modules the are compiled for python2.7 not python 3
So i am trying to build cx_freeze from source and i am facing this error when i run sudo python3 setup.py build
here's the error
adding base module named weakref
running build
running build_py
running build_ext
x86_64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict
prototypes -g -fstack-protector-strong -Wformat -Werror=format
security -D_FORTIFY_SOURCE=2 -fPIC -Ibuild/temp.linux-x86_64-3.4
I/usr/include/python3.4m -c source/bases/Console.c -o
build/temp.linux-x86_64-3.4/source/bases/Console.o
x86_64-linux-gnu-gcc -pthread build/temp.linux-x86_64
3.4/source/bases/Console.o -L/usr/lib/python3.4/config-3.4m-x86_64
linux-gnu -lpython3.4 -o build/lib.linux-x86_64
3.4/cx_Freeze/bases/Console -Xlinker -export-dynamic -Wl,-O1 -Wl,
Bsymbolic-functions -lpthread -ldl -lutil -lm -lrt -lexpat -L/usr/lib
-lz -lexpat -s
/usr/bin/ld: cannot find -lz
collect2: error: ld returned 1 exit status
error: command 'x86_64-linux-gnu-gcc' failed with exit status 1'

Install zlib1g-dev :
sudo apt install zlib1g-dev
then install cx_freeze for python:
pip install cx_freeze
I've tried that on Ubuntu 18.04 and Python 3.6 and worked.

I had exactly the same problem. As suggested in this answer you just need to install the dependencies first:
pip3 install zlib1g-dev
Then sudo python3 setup.py build

Clang linker issues when installing Distance python library

I'm trying to install Distance for python on my mac (OS X Yosemite).
After downloading the package and unpacking it, I run (as described on their page):
python setup.py install --with-c
From this I get the following error message:
running build_ext
building 'distance.cdistance' extension
gcc -fno-strict-aliasing -I/Users/me/anaconda/envs/name/include - arch x86_64 -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -I/Users/me/anaconda/envs/name/include/python2.7 -c cdistance/distance.c -o build/temp.macosx-10.5-x86_64-2.7/cdistance/distance.o
gcc -bundle -undefined dynamic_lookup -L/Users/me/anaconda/envs/name/lib -arch x86_64 -arch x86_64 build/temp.macosx-10.5-x86_64-2.7/cdistance/distance.o -L/Users/me/anaconda/envs/name/lib -o build/lib.macosx-10.5-x86_64-2.7/distance/cdistance.so
ld: library not found for -lgcc_s.10.5
clang: error: linker command failed with exit code 1 (use -v to see invocation)
error: command 'gcc' failed with exit status 1
From what I understood from several posts like this one or this previously asked question, it looks like clang, which is called through the command gcc, can't find the libgcc library.
I ran find /usr/ -name libgcc*and this if what I get:
/usr//lib/libgcc_s.1.dylib
/usr//lib/libgcc_s.10.4.tbd
/usr//lib/libgcc_s.10.5.tbd
/usr//local/Cellar/gcc/5.2.0/lib/gcc/5/gcc/x86_64-apple-darwin14.4.0/5.2.0/i386/libgcc.a
/usr//local/Cellar/gcc/5.2.0/lib/gcc/5/gcc/x86_64-apple-darwin14.4.0/5.2.0/i386/libgcc_eh.a
/usr//local/Cellar/gcc/5.2.0/lib/gcc/5/gcc/x86_64-apple-darwin14.4.0/5.2.0/libgcc.a
/usr//local/Cellar/gcc/5.2.0/lib/gcc/5/gcc/x86_64-apple-darwin14.4.0/5.2.0/libgcc_eh.a
/usr//local/Cellar/gcc/5.2.0/lib/gcc/5/libgcc_ext.10.4.dylib
/usr//local/Cellar/gcc/5.2.0/lib/gcc/5/libgcc_ext.10.5.dylib
/usr//local/Cellar/gcc/5.2.0/lib/gcc/5/libgcc_s.1.dylib
/usr//local/Cellar/gcc/5.2.0/lib/gcc/5/libgcc_s_ppc64.1.dylib
/usr//local/Cellar/gcc/5.2.0/lib/gcc/5/libgcc_s_x86_64.1.dylib
/usr//local/gfortran/lib/gcc/x86_64-apple-darwin14/5.1.0/i386/libgcc.a
/usr//local/gfortran/lib/gcc/x86_64-apple-darwin14/5.1.0/i386/libgcc_eh.a
/usr//local/gfortran/lib/gcc/x86_64-apple-darwin14/5.1.0/libgcc.a
/usr//local/gfortran/lib/gcc/x86_64-apple-darwin14/5.1.0/libgcc_eh.a
/usr//local/gfortran/lib/libgcc_ext.10.4.dylib
/usr//local/gfortran/lib/libgcc_ext.10.5.dylib
/usr//local/gfortran/lib/libgcc_s.1.dylib
/usr//local/gfortran/lib/libgcc_s_ppc64.1.dylib
/usr//local/gfortran/lib/libgcc_s_x86_64.1.dylib
And now I'm stuck because I don't know what to do next. Basically the question is: how do I make clang to know where the library is ?

I solved the issue thanks to this link which showed that this is a very recent issue with Xcode6.
You just need to upgrade Xcode to Xcode7 and set it up as your default toolkit chain. Easy.

Not able to install lxml verison 3.3.5 in ubuntu

I am using openpyxl python package in my application. I am getting the following message when using the same.
/usr/local/lib/python2.7/dist-packages/openpyxl/init.py:31:
UserWarning: The installed version of lxml is too old to be used with
openpyxl
warnings.warn("The installed version of lxml is too old to be used with openpyxl")
Openpyxl requires lxml version 3.2.5 or above, and the version in my machine is 3.2.0. When I try to upgrade lxml to the latest version ie
3.3.5, it is getting interrupted with the following message.
i686-linux-gnu-gcc -pthread -shared -Wl,-O1 -Wl,-Bsymbolic-functions -Wl,-Bsymbolic-functions -Wl,-z,relro -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -D_FORTIFY_SOURCE=2 -g -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security build/temp.linux-i686-2.7/src/lxml/lxml.etree.o -lxslt -lexslt -lxml2 -lz -lm -o build/lib.linux-i686-2.7/lxml/etree.so
/usr/bin/ld: cannot find -lz
collect2: error: ld returned 1 exit status
error: command 'i686-linux-gnu-gcc' failed with exit status 1
----------------------------------------
Rolling back uninstall of lxml
Replacing /usr/lib/python2.7/dist-packages/lxml
Replacing /usr/lib/python2.7/dist-packages/lxml-3.2.0.egg-info
Cleaning up...
Removing temporary dir /tmp/pip_build_root...
Command /usr/bin/python -c "import setuptools;__file__='/tmp/pip_build_root/lxml/setup.py';exec(compile(open(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-ov0PUy-record/install-record.txt --single-version-externally-managed failed with error code 1 in /tmp/pip_build_root/lxml
I need help in resolving the issue.
PS:- I have already installed lxml dependent packages python-dev, libxml2-dev and libxslt1-dev in my machine.

sudo pip install --upgrade lxml

On Ubuntu (and other Debian derivatives), before you build some piece of software, ensure that its build dependencies are installed. Using your example, run this:
sudo apt-get build-dep python-lxml
That is likely going to require a whole bunch of packages, one of which is zlib1g-dev, as mentioned.

I think what you're missing is zlib1g-dev.
sudo apt-get install zlib1g-dev
Running above command will solve the issue.