Ruby extension in C, LoadError - ruby-on-rails

On my own computer I compiled a Ruby extension writen in C. Then I added require 'mytest/mytest' to my controller and it works. Then I moved the files to the server and when I start Mongrel I have the message that:
cannot open shared object file: No such file or directory - {path_to_file}/mytest.so (LoadError)
If I follow that path there is a file mytest.so.
The permissions on mytest.so are set to 0777 and full path is checked, still the same.
can not recompile becouse i don't have gcc on production serv.
Do you have any ideas?

It's probably different architecture, i.e. you had i386, and this is x86_64. Check with uname -a and file mytest.so

yeah you're probably going to need to recompile that binary extension--you can check for dependencies with the ldd command

Related

Ruby on Rails - bin files shebang causing issues (Mac)

So for the files in the /bin directory of a normal rails installation (bin/rails, bin/rake, bin/bundle), the shebang at the top of the file is:
#!/usr/bin/env ruby.exe
But when I run bin/rails, for example, I get the error:
env: ruby.exe: No such file or directory
When I remove the .exe from the end of the shebang, everything works fine. But I was just curious:
Why is this necessary
How to deal with versioning, since the other developer working on this doesn't need to remove the .exe. It's suggested to keep the bin folder in the repo, so I'd prefer to just get the .exe version working if anything.
There are no .exe files on Mac OS X or on Linux. On those platforms the Ruby executable is just called ruby.
For compatibility to those operating systems, your first line should look like this:
#!/usr/bin/env ruby

Updated my path and now my program can't find my gems

I was having some trouble installing the gem libv8. Apparently I need to have python installed. I installed Python and was attempting to update my path with command from another forum:
SET PATH=C:[Ruby Directory]\bin;C:[Python Directory]
or in my case:
SET PATH=C:\Ruby192\bin;C:\Python27
I am not strong with paths and I can't figure out what I did. Now my environment can't find my Ruby directory.
Can someone explain what I did and how I might fix it?
That is most likely because your PATH variable already had a bunch of stuff that you simply throwed away with that line:
echo %PATH%
# a bunch of stuff
SET PATH=C:\Ruby192\bin;C:\Python27
echo %PATH%
# C:\Ruby192\bin;C:\Python27
You can try to append to it instead instead:
set PATH=%PATH%;C:\Ruby192\bin;C:\Python27
echo %PATH%
# a bunch of stuff plus C:\Ruby192\bin;C:\Python27
This change will be avalid for your terminal session only. Closing it and open again should restore the default path. If you need to make it permanent, you need to change your path throught the windows (for example, following this instructions)

Rspec errors in Rails app using Nitrous.io - 'cannot open shared object file'

When I run bundle exec rspec spec/ I get the following messages in the console:
Could not open library 'libgtkmm-2.4': libgtkmm-2.4: cannot open shared object file: No such file or directory.
Could not open library 'libgtkmm-2.4.so': libgtkmm-2.4.so: cannot open shared object file: No such file or directory.
Could not open library 'libgtkmm-2.4.so.1': libgtkmm-2.4.so.1: cannot open shared object file: No such file or directory.
Could not open library 'libgtkmm-3.0': libgtkmm-3.0: cannot open shared object file: No such file or directory.
Could not open library 'libgtkmm-3.0.so': libgtkmm-3.0.so: cannot open shared object file: No such file or directory.
Could not open library 'libgtkmm-3.0.so.1': libgtkmm-3.0.so.1: cannot open shared object file: No such file or directory
But, all of the tests pass and my app works just fine. Can anyone fill me in on what may have happened? Should I just scrap this box and clone my repo into a fresh one? I'm using Ruby 2.0.0p247 and Rails 4.0.2 in a Nitrous.io box. Thanks.
Even though unrelated (thank google for finding this), I have been trying to install Nitrogen for Ubuntu today. I get the same error. Seems like a specific GTK library has gone missing recently from either your system or your distro's repository (if you're even using Linux).
If you're using a Linux system, install the libgtkmm packages and if you're lucky enough, your missing library will be in one of those.
Use in Ubuntu this to install all of them:
sudo apt-get install libgtkmm*
Hope this helps.

.gemrc file specification

I searched everywhere to find the .gemrc file specification but I haven't succeed.
Does anyone know where I can find it?
gem looks for a configuration file .gemrc in your home directory, although you can specify another file on the command-line if you wish (with the --config-file modifier).
There are three things you can specify in the configuration file:
command-line arguments to be used every time gem runs
command-line options for ’’RDoc’’ (used when generating documentation)
GEM_PATH settings
More at gem environment command doc.
'Home' is a Linux/Mac term. What is refers to is the folder where a user's settings appear. You can find out where your settings directory is by doing the following:
on Unix/Linux, open a terminal and type the following command:
echo $HOME
on Windows, open a command-prompt and type the following command:
echo %USERPROFILE%
For me (in Windows 7), this is C:\Users[name]. However, looks like Ruby doesn't set up your .gemrc in that folder by default. Instead, you have to create the file. Open a text editor, copy the YAML style code you need (documentation), and save the file as .gemrc in your home directory (make sure you select all files, not '.txt').
These settings will only affect that individual user. If it's your personal computer, however, you probably don't need to change the settings for all users.
An updated gemrc specification is available at RubyGems Guides (under 'gem environment'). Note that /etc/gemrc applies to all users, while ~/.gemrc applies to an individual.
If the key is a gem command (for example, install:), it specifies arguments to be used with that command.
Here are the other keys that can be specified:
:sources: A YAML array of remote gem repositories to install gems from
:verbose: Verbosity of the gem command. false, true, and :really are the levels
:update_sources: Enable/disable automatic updating of repository metadata
:backtrace: Print backtrace when RubyGems encounters an error
:gempath: The paths in which to look for gems
All of the answers here at time of writing are wrong because the obnoxious website keeps changing. It is at this moment here:
https://guides.rubygems.org/command-reference/#gem-environment
Obviously you should expect it to change constantly at this point.

Including ~/opt/lib libraries in a Passenger Rails App

I'm having trouble getting a rails app on Dreamhost's Passenger to see compiled libraries in my ~/opt/lib directory. I have to put them here because I don't have root access.
I can boot up my app in ./script/console and it sees them libraries just fine because I updated my .bash_profile's LD_LIBRARY_PATH environment variable to include ~/opt/lib.
I've tried putting ENV['LD_LIBRARY_PATH'] = '~/opt/lib' in my environment.rb file but it doesn't seem too help. I get the following error from Passenger when I navigate to my site:
libodbcinst.so.1: cannot open shared object file: No such file or directory - /home/username/opt/lib/odbc.so
Anyone have experience with this?
Thanks
I had similar issue with Passenger that I described in http://blog.rayapps.com/2008/05/21/using-mod_rails-with-rails-applications-on-oracle/
But in your case this migth not work as you will not be able to change Dreamhost's httpd.conf file.
Other thing that you can try is to set LD_LIBRARY_PATH in .bashrc - according to http://www.wavethenavel.com/jonathanpenn/2008/09/08/bootstrapping-a-dreamhost-account-for-rails-and-git/ this has worked in Dreamhost's case. Have not verified that Passenger will execute .bashrc before launching ruby.
Using .bashrc won't work, as the library path that Passenger uses is the one that Apache loads on boot. There is no way it would look at a user's directory as that would be a major security issue.
The environment.rb way sounds like the way to go, though you might want to append to LD_LIBRARY_PATH instead. Also I'd make sure to use the full path to that directory just in case.
Alternatively you might be able to use .htaccess directives, similar to what is described # http://wiki.rubyonrails.org/rails/pages/HowToUseOracleWithFastCGI
This is an old thread, but for completeness this is how to achieve your goal:
Do not set the LD_LIBRARY_PATH if possible - it's horrendous.
As you do not have control over the environment that the Apache
user's environment, attempting to set a LD_LIBRARY_PATH env var per
the methods above will not work anyway.
Set the LDFLAGS environment variable with link and record path flags set prior to compiling the library files to set the correct search paths - e.g.:
export LDFLAGS="-L$HOME/opt/lib -R$HOME/opt/lib"
Once compiled, the files will have the correct links set to the relevant libraries. You can check this using the ldd command line tool - e.g.:
ldd /$HOME/your/custom/complied/library/file.so

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