Example problem:
from runconfigs.config:
[full]
 ...

THINGS_LIST [system #{getenv THING_ORACLE_EXE} listem]
OKSTUFF    hello

% megatest -showrunconfig
THINGS_LIST expected_value
OKSTUFF hello

% megatest -showrunconfig -target full
OKSTUFF hello
  **THINGS_LIST does not appear**