Compiling NuPIC on Ubuntu 15


Install some basic depedencies

sudo apt-get update -y
sudo apt-get install git cmake python-dev -y

Clone nupic.core and nupic

git clone
git clone

Set some environment vars

These point to our checkout directories. We’ll need them later for running tests and scripts. (You’ll probably want this in your .bashrc or .bash_profile.)

export NUPIC=$HOME/nupic
export NUPIC_CORE=$HOME/nupic.core

Get the latest pip

Notice we are not using apt-get because it provides a very old version of pip that is hard to update properly.

curl | sudo python

Downgrade to GCC 4.9

Ubuntu 15 comes with GCC 5.2, which doesn’t yet work with NuPIC.

sudo apt-get install gcc-4.9 g++-4.9 -y

Now gcc/g++ 4.9 is installed, but not the default. We’ll use the update-alternatives method to properly set up both compiler versions, making it easy to switch between them. See this article for a good explanation.

sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-5 10
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.9 20
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-5 10
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.9 20

Now we switch both gcc and g++ to 4.9:

> sudo update-alternatives --config gcc
There are 2 choices for the alternative gcc (providing /usr/bin/gcc).

  Selection    Path              Priority   Status
* 0            /usr/bin/gcc-4.9   20        auto mode
  1            /usr/bin/gcc-4.9   20        manual mode
  2            /usr/bin/gcc-5     10        manual mode

Simply input 1 or hit return. Now you should be using gcc 4.9:

> gcc --version
gcc (Ubuntu 4.9.3-5ubuntu1) 4.9.3

Do the same for g++:

> sudo update-alternatives --config g++
There are 2 choices for the alternative g++ (providing /usr/bin/g++).

  Selection    Path              Priority   Status
* 0            /usr/bin/g++-4.9   20        auto mode
  1            /usr/bin/g++-4.9   20        manual mode
  2            /usr/bin/g++-5     10        manual mode

Press <enter> to keep the current choice[*], or type selection number: 
> g++ --version
g++ (Ubuntu 4.9.3-5ubuntu1) 4.9.3

NuPIC Core

Install nupic.core python dependencies

This takes awhile because numpy!

pip install -r bindings/py/requirements.txt --user

Install pycapnp

This will install the python Capnproto bindings and the C++ Capnproto program.

pip install pycapnp --user

Configure and generate C++ build files

See the README for details about the following commands.

mkdir -p $NUPIC_CORE/build/scripts
cd $NUPIC_CORE/build/scripts
cmake $NUPIC_CORE -DCMAKE_INSTALL_PREFIX=../release -DPY_EXTENSIONS_DIR=$NUPIC_CORE/bindings/py/nupic/bindings


Note: The -j3 option specifies ‘3’ as the maximum number of parallel jobs/threads that Make will use during the build in order to gain speed. However, you can increase this number depending your CPU.

make -j3


collect2: error: ld returned 1 exit status
src/CMakeFiles/connections_performance_test.dir/build.make:99: recipe for target 'src/connections_performance_test' failed
make[2]: *** [src/connections_performance_test] Error 1
CMakeFiles/Makefile2:334: recipe for target 'src/CMakeFiles/connections_performance_test.dir/all' failed
make[1]: *** [src/CMakeFiles/connections_performance_test.dir/all] Error 2
Makefile:136: recipe for target 'all' failed
make: *** [all] Error 2

Full console output.


Stay in the $NUPIC_CORE/build/scripts directory.

make install