Re: [PATCH] test-lib: fix non-functioning GIT_TEST_MAINT_SCHEDULER fallback

> When environment variable GIT_TEST_MAINT_SCHEDULER is set, `git
> maintenance` invokes the command specified as the variable's value
> rather than invoking the actual underlying platform-specific scheduler
> management command. By setting GIT_TEST_MAINT_SCHEDULER to some suitable
> value, test authors can therefore validate behavior of "destructive"
> `git maintenance` commands without having to worry about clobbering the
> user's own local scheduler configuration.
>
> In order to protect an absent-minded test author from forgetting to set
> GIT_TEST_MAINT_SCHEDULER in the local test script (and thus clobbering
> his or her own scheduler configuration), t/test-lib.sh assigns an
> "immediately error-out" value to GIT_TEST_MAINT_SCHEDULER by default
> which should ensure that the problem will be caught and reported before
> any damage can be done to the configuration of the person running the
> tests.
>
> Unfortunately, however, t/test-lib.sh neglects to export
> GIT_TEST_MAINT_SCHEDULER, which renders the default "error-out"
> assignment worthles. Fix this by exporting the variable as originally
> intended.