Bugs: Mojo Test - Crashes when non-test file contains a struct with a parameter

EzRyder · October 20, 2025, 4:41pm

Apparently mojo test is being deprecated (forum). Below a link explaining how to update test files to use TestSuite and a shell script.
I’ve updated a couple of my test files in an existing project and it seems to work OK. I can also run individual tests within a test file by using a symlink to the srcfolder to satisfy imports. This method does not follow the symlink to trigger #5050, so I’m happy.

github.com/modular/modular

mojo/proposals/mojo-test-deprecation.md

main

# Removing `mojo test`

Author: Laszlo Kindrat
Date: Oct 13, 2025
Status: Accepted.

The `mojo test` utility has not gained meaningful adoption within Modular since
its inception two years ago. In mid-2024, it was deprioritized and (aside from a
few fixes shortly after) became unmaintained. This document lays out rationale
for removing it, and how we would go about building something better.

## What `mojo test` does and does not do today

While `mojo test` used to depend on the REPL to easily introspect IR (and maybe
to one day integrate with a debugger), this made it error-prone and slow: the
REPL uses a different compilation model than `mojo build` and `mojo run`, so
what `mojo test` ran wasn’t exactly what the user wrote. For this reason (and
the consequence that it might not allow testing on GPUs) this dependency was
removed, and `mojo test` now performs test file discovery within a given path,
unit test (i.e. function) discovery within test files, and the execution of the

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Bugs: Mojo Test - Crashes when non-test file contains a struct with a parameter

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