Re: [PATCH] t/perf: fix test_export() failure with BSD `sed`

> That's almost good enough, but test_export() needs to accumulate the
> to-be-exported variables across multiple calls, so the non-recursive
> definition would likely be:
>
>     test_export () {
>         test_export_="$test_export_ $*"
>     }
>
> which would make a nice cleanup atop this portability-fix patch.