set var "in main!"
set other "this shouldn't change"
echo "So far var         is ${var}"
echo "... and __FILE__   is ${__FILE__}"
echo "... and other      is ${other}"
echo "... and child_only is ${child_only}"
echo "About to load child.bxt..."
load load/child.bxt "var=overriden"
echo "Back in main var   is ${var}"
echo "... and __FILE__   is ${__FILE__}"
echo "... and other      is ${other}"
echo "... and child_only is ${child_only}"
assertv "load.bxt$" "${__FILE__}"
assertv "^this shouldn't change$" "${other}"
assertv "^in main!$" "${var}"
assertv "^\$\{child_only\}$" "${child_only}"
assertv "^child$" "${retval}"

tryload "this_one_is_invalid.bin"