NationalSecurityAgency/ghidra · error · RuntimeError

No transaction

Error message

No transaction

What it means

Raised by State.require_tx() (commands.py:148-149) when a trace is active but no Trace transaction (STATE.tx) is open. Ghidra traces are mutated inside Transaction objects; mutating the trace tree, memory, or registers outside a transaction is illegal. require_tx() is the precondition gate for nearly every write command.

Source

Thrown at Ghidra/Debug/Debugger-agent-dbgeng/src/main/py/src/ghidradbg/commands.py:149

    def require_trace(self) -> Trace[Extra]:
        if self.trace is None:
            raise RuntimeError("No trace active")
        return self.trace

    def require_no_trace(self) -> None:
        if self.trace != None:
            raise RuntimeError("Trace already started")

    def reset_trace(self) -> None:
        self.trace: Optional[Trace[Extra]] = None
        util.set_convenience_variable('_ghidra_tracing', "false")
        self.reset_tx()

    def require_tx(self) -> Tuple[Trace, Transaction]:
        trace = self.require_trace()
        if self.tx is None:
            raise RuntimeError("No transaction")
        return trace, self.tx

    def require_no_tx(self) -> None:
        if self.tx != None:
            raise RuntimeError("Transaction already started")

    def reset_tx(self) -> None:
        self.tx: Optional[Transaction] = None


STATE = State()


def ghidra_trace_connect(address: Optional[str] = None) -> None:
    """Connect Python to Ghidra for tracing.

    Address must be of the form 'host:port'
    """

View on GitHub (pinned to d5f144c24d)

Solutions

1. Wrap every mutating command pair in ghidra_trace_tx_start('description') ... ghidra_trace_tx_commit().
2. If unsure whether a tx is open, guard it: call require_no_tx-free logic by committing any open tx first, then opening a fresh one.
3. Reset session state with ghidra_trace_disconnect/stop and replay the full connect->start->tx_start sequence.

Example fix

// before
ghidra_trace_putmem(addr, length)   # RuntimeError: No transaction

// after
ghidra_trace_tx_start('record mem')
ghidra_trace_putmem(addr, length)
ghidra_trace_tx_commit()

from ghidradbg.commands import STATE
if getattr(STATE, 'tx', None) is None:
    raise RuntimeError('open a transaction first with ghidra_trace_tx_start')

def tx_is_open() -> bool:
    from ghidradbg.commands import STATE
    return getattr(STATE, 'tx', None) is not None and getattr(STATE, 'trace', None) is not None

try:
    ghidra_trace_putmem(addr, length)
except RuntimeError as e:
    if 'No transaction' in str(e):
        ghidra_trace_tx_start('retry')
        ghidra_trace_putmem(addr, length)
        ghidra_trace_tx_commit()
    else:
        raise

When it happens

Trigger: Calling putmem/putmem_state/delmem/retain_values/etc. (all of which begin with STATE.require_tx()) before opening a transaction with ghidra_trace_tx_start; calling them after ghidra_trace_tx_commit or ghidra_trace_tx_abort reset STATE.tx to None; calling a write command after a trace was just started but no tx was opened.

Common situations: Script that calls ghidra_trace_start then immediately ghidra_trace_putmem, skipping the tx_start step; stale session after a commit where the developer assumed the transaction auto-reopened; copy/paste from a recipe that omitted the transaction bracket.

Related errors

• Transaction already started
• Trace already started
• No transaction
• 'ghidra_trace_connect': missing required argument 'address'
• Invalid argument: {key_list[0]}

AI-assisted analysis of NationalSecurityAgency/ghidra@d5f144c24d (2026-08-14). Data as JSON: /api/errors/66513597f6ffa17f. Report an issue: GitHub.