Can't use hive variable substitution due to dynamic forms

%hive
set tempvar.min_date="2019-01-01";
select ${hiveconf:tempvar.min_date}

"java.lang.RuntimeException: Could not recognize dynamic form with type: hiveconf"

I tried escaping the curly braces with no luck:

%hive
set tempvar.min_date="2019-01-01";
select $\{hiveconf:tempvar.min_date\}

"org.apache.hive.service.cli.HiveSQLException: Error while compiling statement: FAILED: ParseException line 1:7 cannot recognize input near '$' '{' 'hiveconf' in select clause"