bitcoin/doc/build-unix.md

UNIX BUILD NOTES

Some notes on how to build Bitcoin Core in Unix.

(For BSD specific instructions, see build-*bsd.md in this directory.)

Note

Always use absolute paths to configure and compile Bitcoin Core and the dependencies. For example, when specifying the path of the dependency:

../dist/configure --enable-cxx --disable-shared --with-pic --prefix=$BDB_PREFIX

Here BDB_PREFIX must be an absolute path - it is defined using $(pwd) which ensures the usage of the absolute path.

To Build

./autogen.sh
./configure
make
make install # optional

This will build bitcoin-qt as well, if the dependencies are met.

Dependencies

These dependencies are required:

Library	Purpose	Description
libboost	Utility	Library for threading, data structures, etc
libevent	Networking	OS independent asynchronous networking

Optional dependencies:

Library	Purpose	Description
miniupnpc	UPnP Support	Firewall-jumping support
libdb4.8	Berkeley DB	Wallet storage (only needed when wallet enabled)
qt	GUI	GUI toolkit (only needed when GUI enabled)
libqrencode	QR codes in GUI	Optional for generating QR codes (only needed when GUI enabled)
univalue	Utility	JSON parsing and encoding (bundled version will be used unless --with-system-univalue passed to configure)
libzmq3	ZMQ notification	Optional, allows generating ZMQ notifications (requires ZMQ version >= 4.0.0)

For the versions used, see dependencies.md

Memory Requirements

C++ compilers are memory-hungry. It is recommended to have at least 1.5 GB of memory available when compiling Bitcoin Core. On systems with less, gcc can be tuned to conserve memory with additional CXXFLAGS:

./configure CXXFLAGS="--param ggc-min-expand=1 --param ggc-min-heapsize=32768"

Alternatively, or in addition, debugging information can be skipped for compilation. The default compile flags are -g -O2, and can be changed with:

./configure CXXFLAGS="-O2"

Finally, clang (often less resource hungry) can be used instead of gcc, which is used by default:

./configure CXX=clang++ CC=clang

Linux Distribution Specific Instructions

Ubuntu & Debian

Dependency Build Instructions

Build requirements:

sudo apt-get install build-essential libtool autotools-dev automake pkg-config bsdmainutils python3

Now, you can either build from self-compiled depends or install the required dependencies:

sudo apt-get install libevent-dev libboost-system-dev libboost-filesystem-dev libboost-test-dev libboost-thread-dev

BerkeleyDB is required for the wallet.

Ubuntu and Debian have their own libdb-dev and libdb++-dev packages, but these will install BerkeleyDB 5.1 or later. This will break binary wallet compatibility with the distributed executables, which are based on BerkeleyDB 4.8. If you do not care about wallet compatibility, pass --with-incompatible-bdb to configure.

Otherwise, you can build from self-compiled depends (see above).

To build Bitcoin Core without wallet, see Disable-wallet mode

Optional (see --with-miniupnpc and --enable-upnp-default):

sudo apt-get install libminiupnpc-dev

ZMQ dependencies (provides ZMQ API):

sudo apt-get install libzmq3-dev

GUI dependencies:

If you want to build bitcoin-qt, make sure that the required packages for Qt development are installed. Qt 5 is necessary to build the GUI. To build without GUI pass --without-gui.

To build with Qt 5 you need the following:

sudo apt-get install libqt5gui5 libqt5core5a libqt5dbus5 qttools5-dev qttools5-dev-tools

libqrencode (optional) can be installed with:

sudo apt-get install libqrencode-dev

Once these are installed, they will be found by configure and a bitcoin-qt executable will be built by default.

Fedora

Dependency Build Instructions

Build requirements:

sudo dnf install gcc-c++ libtool make autoconf automake libevent-devel boost-devel libdb4-devel libdb4-cxx-devel python3

Optional (see --with-miniupnpc and --enable-upnp-default):

sudo dnf install miniupnpc-devel

ZMQ dependencies (provides ZMQ API):

sudo dnf install zeromq-devel

To build with Qt 5 you need the following:

sudo dnf install qt5-qttools-devel qt5-qtbase-devel

libqrencode (optional) can be installed with:

sudo dnf install qrencode-devel

Notes

The release is built with GCC and then "strip bitcoind" to strip the debug symbols, which reduces the executable size by about 90%.

miniupnpc

miniupnpc may be used for UPnP port mapping. It can be downloaded from here. UPnP support is compiled in and turned off by default. See the configure options for upnp behavior desired:

--without-miniupnpc      No UPnP support miniupnp not required
--disable-upnp-default   (the default) UPnP support turned off by default at runtime
--enable-upnp-default    UPnP support turned on by default at runtime

Berkeley DB

It is recommended to use Berkeley DB 4.8. If you have to build it yourself, you can use the installation script included in contrib/ like so:

./contrib/install_db4.sh `pwd`

from the root of the repository.

Note: You only need Berkeley DB if the wallet is enabled (see Disable-wallet mode).

Boost

If you need to build Boost yourself:

sudo su
./bootstrap.sh
./bjam install

Security

To help make your Bitcoin Core installation more secure by making certain attacks impossible to exploit even if a vulnerability is found, binaries are hardened by default. This can be disabled with:

Hardening Flags:

./configure --enable-hardening
./configure --disable-hardening

Hardening enables the following features:

• Position Independent Executable: Build position independent code to take advantage of Address Space Layout Randomization offered by some kernels. Attackers who can cause execution of code at an arbitrary memory location are thwarted if they don't know where anything useful is located. The stack and heap are randomly located by default, but this allows the code section to be randomly located as well.

  On an AMD64 processor where a library was not compiled with -fPIC, this will cause an error such as: "relocation R_X86_64_32 against `......' can not be used when making a shared object;"

  To test that you have built PIE executable, install scanelf, part of paxutils, and use:

    scanelf -e ./bitcoin
  

  The output should contain:

  TYPE ET_DYN

• Non-executable Stack: If the stack is executable then trivial stack-based buffer overflow exploits are possible if vulnerable buffers are found. By default, Bitcoin Core should be built with a non-executable stack, but if one of the libraries it uses asks for an executable stack or someone makes a mistake and uses a compiler extension which requires an executable stack, it will silently build an executable without the non-executable stack protection.

  To verify that the stack is non-executable after compiling use: scanelf -e ./bitcoin

  The output should contain: STK/REL/PTL RW- R-- RW-

  The STK RW- means that the stack is readable and writeable but not executable.

Disable-wallet mode

When the intention is to run only a P2P node without a wallet, Bitcoin Core may be compiled in disable-wallet mode with:

./configure --disable-wallet

In this case there is no dependency on Berkeley DB 4.8.

Mining is also possible in disable-wallet mode using the getblocktemplate RPC call.

Additional Configure Flags

A list of additional configure flags can be displayed with:

./configure --help

Setup and Build Example: Arch Linux

This example lists the steps necessary to setup and build a command line only, non-wallet distribution of the latest changes on Arch Linux:

pacman -S git base-devel boost libevent python
git clone https://github.com/bitcoin/bitcoin.git
cd bitcoin/
./autogen.sh
./configure --disable-wallet --without-gui --without-miniupnpc
make check

Note: Enabling wallet support requires either compiling against a Berkeley DB newer than 4.8 (package db) using --with-incompatible-bdb, or building and depending on a local version of Berkeley DB 4.8. The readily available Arch Linux packages are currently built using --with-incompatible-bdb according to the PKGBUILD. As mentioned above, when maintaining portability of the wallet between the standard Bitcoin Core distributions and independently built node software is desired, Berkeley DB 4.8 must be used.

ARM Cross-compilation

These steps can be performed on, for example, an Ubuntu VM. The depends system will also work on other Linux distributions, however the commands for installing the toolchain will be different.

Make sure you install the build requirements mentioned above. Then, install the toolchain and curl:

sudo apt-get install g++-arm-linux-gnueabihf curl

To build executables for ARM:

cd depends
make HOST=arm-linux-gnueabihf NO_QT=1
cd ..
./autogen.sh
./configure --prefix=$PWD/depends/arm-linux-gnueabihf --enable-glibc-back-compat --enable-reduce-exports LDFLAGS=-static-libstdc++
make

For further documentation on the depends system see README.md in the depends directory.