View source for Migration to the new standard environment

= What are the differences between the old and the new environments ? =
These differences are listed on the page [[Standard software environments]].

= How can I change which version of <code>StdEnv</code> is my default? =
Our clusters use different versions of <code>StdEnv</code> as their default version. As of August 2020, [[Cedar]] and [[Graham]] use <code>StdEnv/2016.4</code>, while [[Béluga/en|Béluga]] uses <code>StdEnv/2018.3</code>. [[Niagara]] also defaults to <code>StdEnv/2018.3</code> if you run <code>module load CCEnv StdEnv</code>. In the future, we will probably update all of them to use <code>StdEnv/2020</code>. However, users can specify their own default by running the following command (example provided for the 2020 version) 
{{Command|echo "module-version StdEnv/2020 default" >> $HOME/.modulerc}}

= Do I need to reinstall/recompile my code if the <code>StdEnv</code> version changes? =
Yes. If you compile your own code, or install R or Python packages, you should recompile or reinstall the packages you need using the newest version of the standard environment.

= How can I use the old environments ? =
If you have an existing workflow and want to continue to use the same software versions you are using now, simply add 
  module load StdEnv/2018.3
or 
  module load StdEnv/2016.4
to your job script before loading any other modules.  

= Will old environments go away ? = 
No, they ''will not go away''.  They and all the software dependent on them will remain available!  However, Compute Canada staff will no longer install anything into the old environemnts.

= Which environment should I use ? =
If you are starting a new project, or if you want to use a newer version of some software, you should use <tt>StdEnv/2020</tt>. Today you can do this by adding 
  module load StdEnv/2020
to your job script. As of April 1st, 2021, it will be the default and the line will be unnecessary (though not a problem).

= Can I keep the old environment by loading modules in my <code>.bashrc</code> ? =
Loading modules in your <code>.bashrc</code> is '''not recommended'''. Instead, explicitly load modules in your job scripts.