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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
 ```

2. Download [libtorrent](https://github.com/arvidn/libtorrent/releases) and extract:

tar xf libtorrent-rasterbar.tar.gz cd libtorrent-rasterbar

3. Configure:

 ```
 ./configure --enable-python-binding --with-libiconv
  • Missing configure script: (e.g. source code from git) create it with ./autotool.sh (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.

  • 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 [#TemporarySwapFileforRasperryPiorlowmemorysystems temporary swap file]

  • 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 libtorrent-rasterbar.so, a result of Python being unable to find the main library.

  1. Verify libtorrent and the python bindings are installed correctly:
python3 -c "import libtorrent; print (libtorrent.version)"
>> 1.0.6.0

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
  1. Format swap file:
mkswap /.swapfile
  1. Activate swap file:
sudo swapon /.swapfile
  1. Verify swap file is recognized:
swapon -s
  1. Start/restart your libtorrent build.
  2. Disable swap file:
swapoff /.swapfile
  1. Delete swap file:
rm -f /.swapfile

Windows

  1. Download and install/extract these packages:
  2. MS VC++ Compiler for Python
  3. OpenSSL requirement needs building from source.
  4. Python 2.7
  5. MSVC 2008 SP1 Redist Package (x86)
  6. .NET Framework 3.5
  7. Boost
  8. libtorrent

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.

  2. Boost Build Steps:

    In the boost directory run the following:

    bootstrap.bat 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

  3. 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.

  4. libtorrent Build Steps:

    a. Setup the Environmental Variables:

    set BOOST_BUILD_PATH=C:\boost set PATH=%BOOST_BUILD_PATH%;%PATH% b. Navigate to libtorrent Python bindings folder:

    cd C:\libtorrent-rasterbar\bindings\python

    c. 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.

    For libtorrent versions >=1.1:

    b2 libtorrent-link=static boost-link=static release optimization=space encryption=on crypto=openssl include=C:\OpenSSL-Win32\include linkflags=/LIBPATH:C:\OpenSSL-Win32\lib -j%NUMBER_OF_PROCESSORS% --hash

    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:
  • Standalone Debugging Tools for Windows (WinDbg)
  • 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:

``` C:\libtorrent-rasterbar\bindings\python\bin\msvc-9.0\debug\boost-source\geoip-static\link-static\optimization-space\threading-multi

  So the full symbols line should look something like this:

  ```
  srv*;C:\libtorrent-rasterbar\bindings\python\bin\msvc-9.0\debug\boost-source\geoip-static\link-static\optimization-space\threading-multi;C:\Python27\symbols;srv*c:\Symbols*http://msdl.microsoft.com/download/symbols

Debug References: * Mozilla WinDbg stacktrace * Windbg for Beginners

Further Resources