I'm setting up my environment to run the example from lecture #1 (Week01 auction)

All compilations went well but when I try the evaluate in the simulator I always receive:

interpreter Errors
ConnectionError (HttpExceptionRequest Request { host = "localhost" port = 8080 secure = False requestHeaders = [("Accept","application/json;charset=utf-8,application/json"),("Content-Type","application/json;charset=utf-8")] path = "/runghc" queryString = "" method = "POST" proxy = Nothing rawBody = False redirectCount = 10 responseTimeout = ResponseTimeoutDefault requestVersion = HTTP/1.1 } ResponseTimeout)
Please try again or contact support for assistance.

The plutus-playground-server log has the smartcontract and the datum so I think that the call for evaluation was correctly sent but somehow it doesn't come back to the client. In my opinion it's more an issue related to the npm but I don't know how to debug it.

I'm using Ubuntu, all the work done through nix-shell. Plutus tag: 3746610e53654a1167aeb4c6294c6096d16b0502


Further analysis brings me to the conclusion that my system is too slow for the client-server interaction. I saw that the issue is related only to the Auction contract (that's heavier than the demo ones) and watching the trace of the HTTP calls i notice that the /runghc POST takes 34 seconds to give back an answer.

Is there any way i can configure the playground server to consider a timeout higher than 30 secs?


You can try configuring the timeout in cardano/plutus/plutus-playground-client/webpack.config.js

devServer: {
    contentBase: path.join(__dirname, "dist"),
    compress: true,
    port: 8009,
    https: true,
    proxy: {
        "/api": {
            target: 'http://localhost:8080'
            timeout: 1000 * 60 * 10
    } },

There also appears to be a proxyTimeout setting that you can try.

I can't reproduce the error on my end so I'm not sure if this will work, but it seems to make sense that the webpack server is timing out.

Here is a general question posted about webpack dev server timeouts that suggest trying the configurations I mentioned above.



Seems strange for it to be a timeout issue (though I'm not an expert) as the server and the client should both be running on your laptop. I followed the steps as shown in Leet Dev's YT channel - is that what you did to?

  • Yeah, i followed this video but the procedure is quite similar. Actually it's not a network issue, the problem is i'm running the playground on a very cheap hardware configuation (my fault, i admit it!) and the server takes a lot of time to elaborate the contract and the datum. Tracing the calls I can see a timeout call is issued after 30 second from the start of the computation putting the client in an error condition. After that i see the correct answer from the server but at that time nobody is available to catch it. May 27 at 9:33

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