Build libtorrent from source

Check libtorrent documentation for any updates to build procedures.

Ubuntu / Debian

  1. Install dependencies for libtorrent build automatically using build-dep:
    sudo apt-get build-dep libtorrent-rasterbar
    sudo apt-get install checkinstall

OR if that fails manually install them:

sudo apt-get install build-essential checkinstall libboost-system-dev libboost-python-dev libboost-chrono-dev libboost-random-dev libssl-dev
  1. Download libtorrent and extract:
    tar xf libtorrent-rasterbar.tar.gz
    cd libtorrent-rasterbar
  2. Configure:
    ./configure --enable-python-binding --with-libiconv
    • Missing configure script: (e.g. source code from git) create it with ./ (requires extra packages: sudo apt-get install autoconf automake libtool).
    • Logging: Add --enable-logging=default to get logs in the current working directory. verbose and error can also be used.
    • Debug: To create a debug build add --enable-debug=yes.
    • ARM architecture (Raspberry Pi, etc): add --with-boost-libdir=/usr/lib/arm-linux-gnueabihf at the end to avoid boost library error.
  1. Build:
    make -j$(nproc)
    • CPU Cores: The make option -j$(nproc) will utilize all available cpu cores.
    • Non-specific errors: e.g. g++: internal compiler error: Killed (program cc1plus) try using a temporary swap file
  1. Install library and python bindings:
    sudo checkinstall
    sudo ldconfig
    Substituted make install for checkinstall as it creates a deb package for easier removal/re-install by dpkg.
    Running ldconfig avoids an ImportError for, a result of Python being unable to find the main library.
  1. Verify libtorrent and the python bindings are installed correctly:
    python -c "import libtorrent; print libtorrent.version"

Temporary Swap File for Rasperry Pi or low memory systems

Compiling libtorrent requires a lot of memory/swap during the make process ~1-2GB.

If you get an internal error during the make phase on a computer with low memory and/or no swap partition (verify with free -m ) you can try the below procedure.

  1. Create a 1GB empty swap file, (use a drive location that has enough free space):
    dd if=/dev/zero of=/.swapfile bs=1M count=1024
  2. Format swap file:
    mkswap /.swapfile
  3. Activate swap file:
    sudo swapon /.swapfile
  4. Verify swap file is recognized:
    swapon -s
  5. Start/restart your libtorrent build.
  6. Disable swap file:
    swapoff /.swapfile
  7. Delete swap file:
    rm -f /.swapfile


  1. Download and install/extract these packages:

Note: Install or extract to a path without spaces e.g. C:\ drive.

  1. Setup the Windows Command Prompt by executing VC for Python vcvarsall.bat, e.g.:
    "%USERPROFILE%\AppData\Local\Programs\Common\Microsoft\Visual C++ for Python\9.0\vcvarsall.bat"
    Note: If using Visual Studio simple open a Visual Studio 2008 Command Prompt.
  1. Boost Build Steps:

In the boost directory run the following:


Due to a boost bug with VC for Python, need to edit project-config.jam in boost folder to the following:

using msvc : : : <setup>"%USERPROFILE%\\AppData\\Local\\Programs\\Common\\Microsoft\\Visual C++ for Python\\9.0\\vcvarsall.bat" ;

Then run:

b2 --with-system --with-date_time --with-python --with-chrono --with-random
  1. Create a Boost user-config.jam file in the toplevel folder (e.g. C:\boost) with the following to force msvc version:
    using msvc : 9.0 : : <setup>"%USERPROFILE%\\AppData\\Local\\Programs\\Common\\Microsoft\\Visual C++ for Python\\9.0\\vcvarsall.bat" ;
    Note: For Visual Studio, simply using msvc : 9.0 ; is required.
  1. libtorrent Build Steps:
    1. Setup the Environmental Variables:
      set BOOST_BUILD_PATH=C:\boost
    2. Navigate to libtorrent Python bindings folder:
      cd C:\libtorrent-rasterbar\bindings\python
    3. Build libtorrent with Python bindings:
      b2 boost=source libtorrent-link=static geoip=static boost-link=static release optimization=space encryption=openssl include=C:\OpenSSL-Win32\include linkflags=/LIBPATH:C:\OpenSSL-Win32\lib -j%NUMBER_OF_PROCESSORS% --hash 
      Note1: Modify the paths for OpenSSL if installed to a different location.
      Note2: For libtorrent versions <=1.0.6 rename libtorrent-link to link.

Upon a successful build the library file named libtorrent.pyd is created in the current bindings/python directory.

Debugging libtorrent on Windows

  • Download and install just the debug tools:
  • Build libtorrent with debug enabled by changing release to debug in the b2 build line.
  • Open windbg (C:\Program Files\Debugging Tools for Windows (x86)\windbg.exe):
    • File|Open Executable and tick Debug child processes
    • Hit F5 or Go a few times to get the program running
    • After the crash execute: !analyze -v -f.
  • Symbols for libtorrent will be in the build output path:
    So the full symbols line should look something like this:

Debug References:

Further Resources

Last modified 3 months ago Last modified on 01/07/2017 06:12:04 PM