I've been trying to install therubyracer gem on an aarch64 device. I cross-compiled v8 from source (I have got an arm64.release folder resulting from the compilation) but do not know where to put it. I also managed to successfully install libv8 by downloading a .gem file of the version I needed for arm from rubygems and I installed it by running gem install path_to_gem. I also added this to the gemfile:
gem 'libv8', path: '~/.gem/ruby/1.9.1/gems/libv8-3.16.14.11'
However, when I run bundle install and it tries to install therubyracer, I get errors because it tries to compile the dependency again, although it is already installed. I guess it does not detect libv8 is already installed. I also do not know where to put the cross-compiled v8 so my system detects it. I am using a version of an arm64 ubuntu.
Doing gem install therubyracer -v '0.12.2' -- --with-system-v8 does not work either and it tries to compile v8 anyway.
Note that I need everything to be compatible with ruby 1.9.3 and rails 3.2, and I need to use it on a aarch64/arm64 device.
I tried asking on therubyracer github but got no answer since it is quite old.
Unfortunately, V8 3.16.14 (dated February 2013!) does not support arm64. Support for arm64 was landed about a year later, initially under the name "a64", renamed to "arm64" after a couple of weeks.
If you're running an arm32+arm64 "multilib" configuration on your device (which Ubuntu supports but doesn't recommend), you could try getting the 32-bit ARM versions of V8 and therubyracer working. (I don't know how exactly that would be done or whether there will be other obstacles; the libv8 gem mentions an issue but that doesn't seem relevant to your situation.)