## Install Therubyracer Failure

Published: 03 Jul 2016 Category: web_dev

I try to install therubyracer via gem on Windows 10, but keep getting an error associated with -rdynamic flag, which results in failure to build the native extensions:

You can find -rdynamic flag in extconf.rb and Makefile:

C:\Ruby23-x64\lib\ruby\gems\2.3.0\gems\therubyracer-0.12.2\ext\v8\extconf.rb

$CPPFLAGS += " -rdynamic" unless$CPPFLAGS.split.include? "-rdynamic"
$CPPFLAGS += " -fPIC" unless$CPPFLAGS.split.include? "-rdynamic" or RUBY_PLATFORM =~ /darwin/


C:\Ruby23-x64\lib\ruby\gems\2.3.0\gems\therubyracer-0.12.2\ext\v8\Makefile

CPPFLAGS =  -DFD_SETSIZE=2048 -D_WIN32_WINNT=0x0501 -D__MINGW_USE_VC2005_COMPAT $(DEFS)$(cppflags) -Wall -g -rdynamic


Somebody figures it out by changing gcc compiler to version 4.2 (mine is 4.9.3). For some reason the newer gcc version don’t just ignore the -rdynamic flag, which is only present for compiling on Linux and is not actually compatible with Windows and OS X.

https://stackoverflow.com/questions/35741536/trouble-installing-therubyracer-gem-due-to-compiler-issue-on-mac

More detailed explanation is that: -rdynamic passes the flag -export-dynamic to ELF linker, on targets that support it

Executable formats in OS X and Windows are not ELF, thus the option -rdynamic is not supported building for these operating systems.

http://stackoverflow.com/questions/29534519/why-gcc-doesnt-recognize-rdynamic-option

One solution is using an older gcc compiler, like gcc-4.2.

http://preshing.com/20141108/how-to-install-the-latest-gcc-on-windows/

wget http://ftpmirror.gnu.org/gcc/gcc-4.2.4/gcc-4.2.4.tar.gz

wget http://ftpmirror.gnu.org/gcc/gcc-4.2.4/gcc-g++-4.2.4.tar.bz2