@effigies - should we use memoize here, or just call the version check again? in the unlikely, but possible scenario that someone changes a software on the system.

The specific purpose is to memoize so that when calling an interface many times that runs a version check under the hood, we're not spawning an additional process each time.

Under what circumstances would you want to actively support changing versions during a run, and is it worth accounting for that situation by default? Most of the effects are going to be for input spec versioning, which will happen at workflow construction time. If you swap in an incompatible version after that, it should break when it's time to run. But significantly changing the environment is one of those cases where I feel like breaking is both expected and probably a good alternative to silently pressing on.

The one case I can see is if you're working in a Python console, and upgrade software, and for whatever reason you really don't want to start a new console. With this change, you could do interfaces.ants.base.Info._version = None, but we could also add a method or function to clear the cache.

Codecov Report

Merging #2274 into master will increase coverage by 0.01%.
The diff coverage is 68.29%.

@@            Coverage Diff             @@
##           master    #2274      +/-   ##
==========================================
+ Coverage    72.5%   72.52%   +0.01%     
==========================================
  Files        1188     1188              
  Lines       59134    59135       +1     
  Branches     8505     8506       +1     
==========================================
+ Hits        42877    42889      +12     
+ Misses      14871    14860      -11     
  Partials     1386     1386

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@effigies - i'll merge this in a second. the situation really deals with environment where people have long running jobs, but underlying software can get updated without people knowing. while this is not common, as i mentioned earlier, i think with versioning, just like file hashing we cannot rely on the external environment to remain constant.