Assertion failure when using group-by and amount

[taviso]

Test ledger File:

2024/01/01 * Test1
    Expenses:Test                            $1.00
    Assets:Checking
2024/01/01 * Test2
    Expenses:Test                            $1.00
    Assets:Checking

$ ledger --args-only --file test.ldg bal --group-by 'payee' --amount 'amount * 2' ^Expenses:
terminate called after throwing an instance of 'ledger::assertion_failed'
  what():  Assertion failed in "ledger/src/op.h", line 260:void ledger::expr_t::op_t::release() const: refc > 0

$ ledger --version
Ledger 3.3.2-20230330, the command-line accounting tool