TypeError: can't convert Tempfile into StringIO

[pboling]

  1) MyClass#initialize when level is invalid when output to stdout warns
     Failure/Error: subject(:logged) { capture(:stdout) { instance } }
     
     TypeError:
       can't convert Tempfile into StringIO

I have zeroed in on the culprit as the setting of the environment variable CI_CAPTURE. If I run my tests through the ci_reporter rake task (ci:setup:rspec), and do not set CI_CAPTURE, my output tests fail because the output is a Tempfile instead of a String.

If I set CI_CAPTURE=off then it works fine.