Crash on long-running Simnet sessions

[BowTiedRadone]

Describe the Bug
In long-running sessions, a crash occurs after exactly 3,670,015 iterations with one of the following errors:

• Recursive use of an object detected which would lead to unsafe aliasing in Rust
• RuntimeError: unreachable

This issue has been present for a while. Thanks to @hugocaillard’s work in #1617, included in clarinet-sdk version v2.12.0, the issue was mitigated, and performance was significantly improved, allowing roughly twice as many iterations. However, the crash still occurs. Discussions with Hugo suggest this issue is strongly related to memory usage, specifically the Node.js process running the clarinet-sdk session reaching 4 GB of memory at the crash point.

This issue is being opened to facilitate further investigation and in response to reports by users of Rendezvous, which highlights the same crash.

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To Reproduce
Steps to reproduce the issue:

1. Initialize a new Clarinet project:

   clarinet new demo

2. Create a new file named index.js in the root of the project and add the following code:

   import { initSimnet } from "@hirosystems/clarinet-sdk";
   
   const longRunningSimnetSession = async () => {
     const simnet = await initSimnet();
   
     while (true) {
       simnet.mineEmptyBlock();
       console.log(`Iteration ${simnet.blockHeight}`);
     }
   };
   
   await longRunningSimnetSession();

3. Install the required dependencies:

   npm install

4. Run the long-running session:

   node index.js

5. Observe the crash after exactly 3,670,015 iterations. At this point, Node.js reports 4 GB of memory usage:

   Iteration 3670015
   wasm://wasm/01dccebe:1
   
   RuntimeError: unreachable
       at wasm://wasm/01dccebe:wasm-function[5048]:0x4f80f0
       at wasm://wasm/01dccebe:wasm-function[4373]:0x47ad83
       at wasm://wasm/01dccebe:wasm-function[437]:0x2046aa
       at wasm://wasm/01dccebe:wasm-function[1460]:0x351032
       at wasm://wasm/01dccebe:wasm-function[191]:0x142fd4
       at wasm://wasm/01dccebe:wasm-function[838]:0x2a1337
       at wasm://wasm/01dccebe:wasm-function[4394]:0x47afd4
       at wasm://wasm/01dccebe:wasm-function[3033]:0x42db2d
       at Proxy.mineEmptyBlock (/Users/demo/node_modules/@hirosystems/clarinet-sdk-wasm/clarinet_sdk.js:687:26)
       at longRunningSimnetSession (file:///Users/demo/index.js:7:12)
   
   Node.js v22.11.0
   

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Additional Context
The issue consistently occurs after the same number of Simnet iterations (3,670,015) in any app, producing one of the mentioned error messages. See the related issue in Rendezvous. Thanks to @fariedt and @hassan-truscova for highlighting this in Rendezvous.