Global: param = twice
Global: VARNAME = VAR.$${param}
Var_Parse: ${VARNAME} (eval)
Global: VAR.${param} = initial-value
Var_Parse: ${${VARNAME}::=assigned-value} (eval-defined)
Var_Parse: ${VARNAME}::=assigned-value} (eval-defined)
Evaluating modifier ${VAR.${param}::...} on value "initial-value"
Modifier part: "assigned-value"
Global: VAR.${param} = assigned-value
Result of ${VAR.${param}::=assigned-value} is ""
Var_Parse: ${${VARNAME}} != "assigned-value" (eval-defined)
Var_Parse: ${VARNAME}} != "assigned-value" (eval-defined)
Global: .MAKEFLAGS =  -r -k -d v -d
Global: .MAKEFLAGS =  -r -k -d v -d 0
make: Bad modifier ":" for variable ""
mod-assign-empty: value}
make: Bad modifier ":" for variable ""
mod-assign-empty: overwritten}
mod-assign-empty: VAR=overwritten
make: Unknown modifier ":x"

sysv:y
make: Unfinished modifier for "ASSIGN" ('}' missing)

ok=word
make: " echo word; false " returned non-zero status
err=previous
exit status 0