# Build system Our build system is [Rake](https://github.com/ruby/rake). Its functionality is similar to Make, but its DSL is in Ruby. `passenger-install-apache2-module` and `passenger-install-nginx-module` call Rake to compile things. ## Key Rake targets - `rake apache2` — compiles the Apache 2 module, and other parts needed by the Apache integration mode (e.g., the Passenger agent binary). - `rake nginx` — compiles parts needed by the Nginx integration mode (e.g., agent binary). Does *not* compile the Nginx module. - For test suite targets, see [Running tests](RunningTests.md). See more with `rake -T`. ## Concurrent compilation Run `rake -m -j` for concurrent compilation. `` should equal the number of CPU cores. ## Environment variables You can pass environment variables via CLI arguments. These are equivalent: ```bash rake something FOO=123 export FOO=123 && rake something ``` You can persist environment variables in `config.rb`. This file is automatically loaded by Rake. ```ruby # config.rb ENV['FOO'] = '123' ``` ## Customization Customize the build system with environment variables. Boolean options can be set to true, false, 0 or 1. - `OUTPUT_DIR`: where build output is placed. Default: `buildout/` - `EXTRA_PRE_CFLAGS` and `EXTRA_CFLAGS`: insert additional flags to C compiler invocations. One for before our own flags, one for after. Does not cover linking invocations. - `EXTRA_PRE_CXXFLAGS` and `EXTRA_CXXFLAGS`: ditto, but for C++ compiler invocations. - `EXTRA_PRE_LDFLAGS` and `EXTRA_LDFLAGS`: insert additional flags to C/C++ compiler linking invocations. One for before our own flags, one for after. - `EXTRA_PRE_C_LDFLAGS` and `EXTRA_C_LDFLAGS`: ditto, but only applies to C compiler linking invocations. - `EXTRA_PRE_CXX_LDFLAGS` and `EXTRA_CXX_LDFLAGS`: ditto, but only applies to C++ compiler linking invocations. - `USE_CCACHE=` (default: false): wrap compiler invocations in ccache. See also [ccache setup instructions](DevEnvironmentSetup.md#build-caching). - `USE_ASAN=` (default: false): compile with AddressSanitizer. - `USE_UBSAN=` (default: false): compile with UndefinedBehaviorSanitizer. - `OPTIMIZE=` (default: false): compile with optimizations. - `USE_VENDORED_LIBEV=` (default: true): set to false to compile with system-provided libev instead of our vendored one. - `USE_VENDORED_LIBUV=` (default: true): set to false to compile with system-provided libuv instead of our vendored one.