Source code is available in SVN and as a separate package with every NSIS distribution.
To build NSIS Python and SCons must be installed. Currently, the supported version of SCons is version 0.96.93. Any version of Python above 1.6 is supported.
To build, open a console, change the working directory to the root directory of NSIS and type scons. That's it. For example:
C:\>cd dev\nsis C:\dev\nsis>scons scons: Reading SConscript files ... Using Microsoft tools configuration Checking for main() in C library gdi32... (cached) yes Checking for main() in C library user32... (cached) yes Checking for main() in C library version... (cached) yes Checking for main() in C library pthread... (cached) no Checking for main() in C library stdc++... (cached) no Checking for main() in C library iconv... (cached) no Checking for main() in C library libiconv... (cached) no scons: done reading SConscript files. scons: Building targets ... ...
To install the built files, type:
scons PREFIX="C:\Program Files\NSIS" install
To create an installer (only on Windows), type:
scons dist-installer
To create a distribution zip file, type:
scons dist-zip
To create both, type:
scons dist
To get a complete list of options that the build system has to offer, type:
scons -h
To get a complete list of options SCons has to offer, type:
scons -H