%preserve doesn't appear to preserve vars (or functions)

[pointo1d]

Hey all,

I have script that I source in order to provide common/library env vars & functions and am struggling to test that the expected env vars & function(s) exist as a result of the inclusion. MWE - assuming an included file of t.sh...

export -A SOME_VAR

some-func() {
  :
}

... and t_spec.sh containing...

It "GP: includes successfully with correct defaults"
      preserve() { %preserve SOME_VAR ; }
      AfterRun preserve

      When run source src/main/${FNNAME//./\/}.sh
      The status should be success
      The stdout should equal ''
      The stderr should equal ''
      The variable SOME_VAR should exist
      The function some-func should exist
 End

My problem is that neither of the assertions pass since the assertions consider that the subjects i.e. SOME_VAR & some-func, are undefined - as follows...

$ shellspec t_spec.sh 
Running: /bin/bash [bash 5.0.17(1)-release]
F

Examples:
  1) GP: includes successfully with correct defaults
     When run source t.sh

     1.1) The variable SOME_VAR should exist

            expected <unset> to exist

          # t_spec.sh:9

     1.2) The function some-func should exist

            expected "some-func" to exist

          # t_spec.sh:10

Finished in 0.09 seconds (user 0.09 seconds, sys 0.00 seconds)
1 example, 1 failure


Failure examples / Errors: (Listed here affect your suite's status)

shellspec t_spec.sh:1 # 1) GP: includes successfully with correct defaults FAILED

But, informally, I know that the script works perfectly well when run "in anger".

BTW, I use run source since I want to ensure that the inclusion doesn't blow up the whole test run.

Any & all help very greatly appreciated