chore: pin pragma

src/bridge/AbsBridge.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/nitro/blob/master/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.4;
+pragma solidity 0.8.9;
 
 import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
 import "@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol";

src/bridge/AbsInbox.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/nitro/blob/master/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.4;
+pragma solidity 0.8.9;
 
 import {
     DataTooLarge,

src/bridge/AbsOutbox.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/nitro/blob/master/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.4;
+pragma solidity 0.8.9;
 
 import {
     AlreadyInit,

src/bridge/Bridge.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.4;
+pragma solidity 0.8.9;
 
 import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
 import "@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol";

src/bridge/ERC20Bridge.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/nitro/blob/master/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.4;
+pragma solidity 0.8.9;
 
 import "./AbsBridge.sol";
 import "./IERC20Bridge.sol";

src/bridge/ERC20Inbox.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/nitro/blob/master/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.4;
+pragma solidity 0.8.9;
 
 import "./AbsInbox.sol";
 import "./IERC20Inbox.sol";

src/bridge/ERC20Outbox.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/nitro/blob/master/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.4;
+pragma solidity 0.8.9;
 
 import "./AbsOutbox.sol";
 import {IERC20Bridge} from "./IERC20Bridge.sol";

src/bridge/GasRefunder.sol

@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.8.7;
+pragma solidity 0.8.9;
 
 import "../libraries/IGasRefunder.sol";
 

src/bridge/Inbox.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.4;
+pragma solidity 0.8.9;
 
 import {
     NotOrigin,

src/bridge/Messages.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 library Messages {
     function messageHash(

src/bridge/Outbox.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.4;
+pragma solidity 0.8.9;
 
 import "./AbsOutbox.sol";
 

src/bridge/SequencerInbox.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import {
     AlreadyInit,

src/chain/CacheManager.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/nitro/blob/master/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "../precompiles/ArbOwnerPublic.sol";
 import "../precompiles/ArbWasm.sol";

src/challenge/ChallengeLib.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "../state/Machine.sol";
 import "../state/GlobalState.sol";

src/challenge/ChallengeManager.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "../libraries/DelegateCallAware.sol";
 import "../osp/IOneStepProofEntry.sol";

src/challenge/IChallengeManager.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "../state/Machine.sol";
 import "../bridge/IBridge.sol";

src/challenge/IChallengeResultReceiver.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 interface IChallengeResultReceiver {
     function completeChallenge(

src/libraries/AddressAliasHelper.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 library AddressAliasHelper {
     uint160 internal constant OFFSET = uint160(0x1111000000000000000000000000000000001111);

src/libraries/AdminFallbackProxy.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "@openzeppelin/contracts/proxy/Proxy.sol";
 import "@openzeppelin/contracts/proxy/ERC1967/ERC1967Upgrade.sol";

src/libraries/ArbitrumChecker.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/nitro/blob/master/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "../precompiles/ArbSys.sol";
 

src/libraries/Constants.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.4;
+pragma solidity 0.8.9;
 
 uint64 constant NO_CHAL_INDEX = 0;
 

src/libraries/CryptographyPrimitives.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 ///      This algorithm has been extracted from the implementation of smart pool (https://github.com/smartpool)
 library CryptographyPrimitives {

src/libraries/DecimalsConverterHelper.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 

src/libraries/DelegateCallAware.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import {NotOwner} from "./Error.sol";
 

src/libraries/DoubleLogicUUPSUpgradeable.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import {DoubleLogicERC1967Upgrade} from "./AdminFallbackProxy.sol";
 import "@openzeppelin/contracts/proxy/utils/UUPSUpgradeable.sol";

src/libraries/Error.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.4;
+pragma solidity 0.8.9;
 
 /// @dev Init was already called
 error AlreadyInit();

src/libraries/GasRefundEnabled.sol

@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: BUSL-1.1
 
 // solhint-disable-next-line compiler-version
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "./IReader4844.sol";
 import "./IGasRefunder.sol";

src/libraries/MerkleLib.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.4;
+pragma solidity 0.8.9;
 
 import {MerkleProofTooLong} from "./Error.sol";
 

src/libraries/MessageTypes.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.4;
+pragma solidity 0.8.9;
 
 uint8 constant L2_MSG = 3;
 uint8 constant L1MessageType_L2FundedByL1 = 7;

src/libraries/UUPSNotUpgradeable.sol

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: MIT
 // OpenZeppelin Contracts (last updated v4.5.0) (proxy/utils/UUPSUpgradeable.sol)
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "@openzeppelin/contracts/interfaces/draft-IERC1822.sol";
 import {DoubleLogicERC1967Upgrade} from "./AdminFallbackProxy.sol";

src/mocks/HostioTest.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/nitro/blob/master/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.24;
+pragma solidity 0.8.24;
 
 /*
  * HostioTest is a test contract used to compare EVM with Stylus.

src/osp/HashProofHelper.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "../libraries/CryptographyPrimitives.sol";
 

src/osp/IOneStepProofEntry.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "./IOneStepProver.sol";
 

src/osp/IOneStepProver.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "../state/Machine.sol";
 import "../state/Module.sol";

src/osp/OneStepProofEntry.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "../state/Deserialize.sol";
 import "../state/Machine.sol";

src/osp/OneStepProver0.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "../state/Value.sol";
 import "../state/Machine.sol";

src/osp/OneStepProverHostIo.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "../state/Value.sol";
 import "../state/Machine.sol";

src/osp/OneStepProverMath.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "../state/Value.sol";
 import "../state/Machine.sol";

src/osp/OneStepProverMemory.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "../state/Value.sol";
 import "../state/Machine.sol";

src/rollup/AbsRollupEventInbox.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/nitro/blob/master/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "./IRollupEventInbox.sol";
 import "../bridge/IBridge.sol";

src/rollup/BridgeCreator.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "../bridge/Bridge.sol";
 import "../bridge/SequencerInbox.sol";

src/rollup/Config.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "../state/GlobalState.sol";
 import "../state/Machine.sol";

src/rollup/DeployHelper.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/OffchainLabs/nitro-contracts/blob/main/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import {IInbox} from "../bridge/IInbox.sol";
 import {IInboxBase} from "../bridge/IInboxBase.sol";

src/rollup/ERC20RollupEventInbox.sol

@@ -2,7 +2,7 @@
 // For license information, see https://github.com/nitro/blob/master/LICENSE
 // SPDX-License-Identifier: BUSL-1.1
 
-pragma solidity ^0.8.0;
+pragma solidity 0.8.9;
 
 import "./AbsRollupEventInbox.sol";
 import "../bridge/IERC20Bridge.sol";