Common Issues

This section has been moved to SpecialCases.


Many of these sections will be labeled with an error that is displayed after running rst. Not all of these errors are fully understood. As a last resort, you can always contact the Computer Science Computing Facility (CSCF) for help. Please keep in mind that provided files are written in full racket.

 Required module lib.rkt not found;

The test script cannot find the library needed. It may be that the file name was misspelled in the options file or not named correctly in the provided. Or, the file may just be missing from the provided. It can actually still run properly with the error message, if the student submitted a file of the same name into their folder.

 Disallowed function some-fun called

This one is straight forward. If you are stuck check all files for use of the disallowed function. This includes the submitted file, the test.rkt file and all files used from provided.

 Evaluator creation error: FAILED - Error creating evaluator, [insert error message] 

There are many different things that can lead to this issue. The best thing to do is read the entire error message; it's usually a long and scary block of characters followed by a small helpful message at the very end. The list bellow are causes and fixes from most likely to least likely.

  • The submission is requiring a library that is not in the list of modules in the options.rkt file. To fix this add the file's name into the modules line in the options file for that question.

  • The submission may be using a banned special form. Some special forms will give the disallowed function error message and some will give a funny error message. Double check the allowed use of lambda and local from the assignment specifications and the what the disallowed.rkt file states.

  • One of the provided files may be requiring a standard racket library. It is unknown why this causes problems. It also seems that there is only an issue for some racket libraries. If it is something just for fun, like a drawing library, then comment out any code related to it and make functions that use it just return empty. Contact the instructor or CSCF if this is not a valid solution.

  • One of the provided libraries may be requiring another file in the provided directory. This error has to do with the load order of the modules. The fix that has been shown to work is to not do this. As a workaround you can copy the code into one big file and provide that as a module. Or, check the order that you specified your modules in the (modules ...) line.

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Topic revision: r2 - 2021-12-17 - AmyHwang
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