# \#debugging **URL:** https://forum.modular.com/tag/debugging/1.md [Latest](https://forum.modular.com/latest.md) · [Categories](https://forum.modular.com/categories.md) · [Tags](https://forum.modular.com/tags.md) --- ## [Debugging example in GPU Puzzles (p09) is outdated](https://forum.modular.com/t/debugging-example-in-gpu-puzzles-p09-is-outdated/3472)
**Author:** [@juandcf](https://forum.modular.com/u/juandcf)\ **Replies:** 0\ **Last updated:** [September 6, 2026, 10:56pm UTC](https://forum.modular.com/t/debugging-example-in-gpu-puzzles-p09-is-outdated/3472 "2026-09-06T22:56:49Z")
Copy-pasting here what I wrote on the Discord Mojo channel: Hello, I have a basic question about gpu puzzles, specifically the Debugging example. Trying to follow the steps in Problem 9 - Essentials but cannot access th… --- ## [Error Logging in With Microsoft](https://forum.modular.com/t/error-logging-in-with-microsoft/3446)
**Author:** [@Gomes](https://forum.modular.com/u/Gomes)\ **Replies:** 1\ **Last updated:** [September 2, 2026, 4:14pm UTC](https://forum.modular.com/t/error-logging-in-with-microsoft/3446 "2026-09-02T16:14:12Z")
Hello everyone, I need help with BentoML. I have an organization with third-party authentication and I’m having a problem logging in with Microsoft. I’m receiving the following error: auth/invalid-credential: Firebase: E… --- ## [Max llm tutorial bug](https://forum.modular.com/t/max-llm-tutorial-bug/3225)
**Author:** [@alix](https://forum.modular.com/u/alix)\ **Replies:** 4\ **Last updated:** [June 13, 2026, 6:18am UTC](https://forum.modular.com/t/max-llm-tutorial-bug/3225 "2026-06-13T06:18:58Z")
alexjacob@ho-sm-ai-proxy02:~/research/max-llm-book$ pixi run serve WARN the lock file is up-to-date but uses an older format (v6), run pixi lock to upgrade to v7 for improved reproducibility :sparkles: Pixi task (serve… --- ## [BentoML deployment randomly stops working](https://forum.modular.com/t/bentoml-deployment-randomly-stops-working/3218)
**Author:** [@kkAtom360](https://forum.modular.com/u/kkAtom360)\ **Replies:** 1\ **Last updated:** [June 9, 2026, 3:25pm UTC](https://forum.modular.com/t/bentoml-deployment-randomly-stops-working/3218 "2026-06-09T15:25:54Z")
Edit: ====== It started working magically again. Now it stopped again with 401 Authorization token error. It seems there might be an issue with your access token or it may not have been set in the header. Error is stil… --- ## [@staticmethod error in test but not deployment](https://forum.modular.com/t/staticmethod-error-in-test-but-not-deployment/3100)
**Author:** [@tedmoore](https://forum.modular.com/u/tedmoore)\ **Replies:** 1\ **Last updated:** [May 22, 2026, 6:42pm UTC](https://forum.modular.com/t/staticmethod-error-in-test-but-not-deployment/3100 "2026-05-22T18:42:28Z")
Greetings, I have struct with a @staticmethod that creates an instance of itself within that @staticmethod. When I run this code it works! Unfortunately, when running a smoke test on this code (mojo build --emit object … --- ## [Some simple changes to package.json make Mojo work better in VSCode](https://forum.modular.com/t/some-simple-changes-to-package-json-make-mojo-work-better-in-vscode/3016)
**Author:** [@INsanE-Alchemist](https://forum.modular.com/u/INsanE-Alchemist)\ **Replies:** 3\ **Last updated:** [May 5, 2026, 4:29pm UTC](https://forum.modular.com/t/some-simple-changes-to-package-json-make-mojo-work-better-in-vscode/3016 "2026-05-05T16:29:34Z")
I don’t know, maybe I’m crazy, and maybe it’s just me, but I’ve had a long standing frustration with writing code in Mojo. Something stupidly simple was just not possible. I have this really trivial project setup, but … --- ## [Multithreading on CPU](https://forum.modular.com/t/multithreading-on-cpu/2805)
**Author:** [@MikeHersee](https://forum.modular.com/u/MikeHersee)\ **Replies:** 0\ **Last updated:** [March 4, 2026, 2:12pm UTC](https://forum.modular.com/t/multithreading-on-cpu/2805 "2026-03-04T14:12:00Z")
I’ve just installed Mojo and was running the standard Life simulations from the examples, removing the time delay and watching the virtual processor activity level to see how much difference Life3 made compared to Life1.… --- ## [Help compiling MLP in MAX](https://forum.modular.com/t/help-compiling-mlp-in-max/2760)
**Author:** [@AndPotap](https://forum.modular.com/u/AndPotap)\ **Replies:** 4\ **Last updated:** [February 23, 2026, 11:43pm UTC](https://forum.modular.com/t/help-compiling-mlp-in-max/2760 "2026-02-23T23:43:09Z")
Hi, I went over the really good content on the MAX LLM book but I can’t seem to get the model to compile. To simplify the problem right now I’m just trying to get the MLP part of the model to compile but without any suc… --- ## [Failed to resolve module path for \`MOGGKernelAPI\`](https://forum.modular.com/t/failed-to-resolve-module-path-for-moggkernelapi/2707)
**Author:** [@AndPotap](https://forum.modular.com/u/AndPotap)\ **Replies:** 1\ **Last updated:** [February 10, 2026, 4:15pm UTC](https://forum.modular.com/t/failed-to-resolve-module-path-for-moggkernelapi/2707 "2026-02-10T16:15:36Z")
I get the following error related to MOGGKernelAPI python3 addition.py Traceback (most recent call last): File "/home/ubu/code\_examples/modular/forum/.pixi/envs/default/lib/python3.13/site-packages/max/engine/api.py",… --- ## [\`has\_apple\_gpu\_accelerator()\` is False on jupyter-lab on my Macbook](https://forum.modular.com/t/has-apple-gpu-accelerator-is-false-on-jupyter-lab-on-my-macbook/2488)
**Author:** [@fzngagan](https://forum.modular.com/u/fzngagan)\ **Replies:** 2\ **Last updated:** [November 29, 2025, 9:30am UTC](https://forum.modular.com/t/has-apple-gpu-accelerator-is-false-on-jupyter-lab-on-my-macbook/2488 "2025-11-29T09:30:31Z")
from sys import has\_apple\_gpu\_accelerator print(has\_apple\_gpu\_accelerator()) gives False on jupyter-lab on my Macbook AIr M4. Is there a way to get it to work in jupyter? Also, can I get syntax highlighting in jupyter f… --- ## [Calling c functions with larger structs by value fails](https://forum.modular.com/t/calling-c-functions-with-larger-structs-by-value-fails/655)
**Author:** [@sbrunk](https://forum.modular.com/u/sbrunk)\ **Replies:** 7\ **Last updated:** [September 28, 2025, 5:16pm UTC](https://forum.modular.com/t/calling-c-functions-with-larger-structs-by-value-fails/655 "2025-09-28T17:16:28Z")
Here’s a minimized example of an issue I ran into, while working on the DuckDB Mojo bindings. I have a c function that expects to be called by value with a struct containing more than 2 elements. Using DLHandle.call, it… --- ## [SIMD loads on the GPU](https://forum.modular.com/t/simd-loads-on-the-gpu/2122)
**Author:** [@jaidmin](https://forum.modular.com/u/jaidmin)\ **Replies:** 2\ **Last updated:** [August 28, 2025, 9:12am UTC](https://forum.modular.com/t/simd-loads-on-the-gpu/2122 "2025-08-28T09:12:11Z")
I have ported a CUDA kernel to Mojo, and verified its correctness. The performance was worse, so I did Nsight Compute analysis and it told: The memory access pattern for global loads from L2 might not be optimal. On ave… --- ## [High Memory Usage](https://forum.modular.com/t/high-memory-usage/2086)
**Author:** [@spacy](https://forum.modular.com/u/spacy)\ **Replies:** 1\ **Last updated:** [August 6, 2025, 12:44pm UTC](https://forum.modular.com/t/high-memory-usage/2086 "2025-08-06T12:44:38Z")
Hi, This code when compiled with mojo build uses 19M of memory according to htop (and 2G of virtual memory) on Linux amd64. What are the reasons for this imho high memory usage? Anything I can do to bring it down? Th… --- ## [Gpu-puzzles: initialization of shared\_a in problem 11](https://forum.modular.com/t/gpu-puzzles-initialization-of-shared-a-in-problem-11/1903)
**Author:** [@TotalOutlier](https://forum.modular.com/u/TotalOutlier)\ **Replies:** 2\ **Last updated:** [July 10, 2025, 11:43pm UTC](https://forum.modular.com/t/gpu-puzzles-initialization-of-shared-a-in-problem-11/1903 "2025-07-10T23:43:23Z")
I am going through the gpu puzzles and really enjoying it, thank you very much for this awesome treat! I am currently at problem 11 and the solution is correct, but a bit confusing around initialization of shared memory… --- ## [Model loading and executing - FlashAttention Issue](https://forum.modular.com/t/model-loading-and-executing-flashattention-issue/1789)
**Author:** [@bsamuel](https://forum.modular.com/u/bsamuel)\ **Replies:** 2\ **Last updated:** [June 28, 2025, 11:27pm UTC](https://forum.modular.com/t/model-loading-and-executing-flashattention-issue/1789 "2025-06-28T23:27:09Z")
Do you have any pointers on resource to help with installation of the models after MAX install and Model install and trying to execute. I am persistently getting FlashAttention error while trying to execute (after instal… --- ## [Test Coverage Reports](https://forum.modular.com/t/test-coverage-reports/1736)
**Author:** [@ThomasTrenty](https://forum.modular.com/u/ThomasTrenty)\ **Replies:** 0\ **Last updated:** [June 25, 2025, 5:15am UTC](https://forum.modular.com/t/test-coverage-reports/1736 "2025-06-25T05:15:11Z")
Hi, It appears that test coverage reports are currently a missing functionality from the mojo test utility (as of nightly release 25.5.0.dev2025061805). Is there a technical issue preventing this functionality from bei… --- ## [Trying to get Mojo debugger to work fully on non-Ubuntu systems](https://forum.modular.com/t/trying-to-get-mojo-debugger-to-work-fully-on-non-ubuntu-systems/1635)
**Author:** [@tristanbiesecker](https://forum.modular.com/u/tristanbiesecker)\ **Replies:** 2\ **Last updated:** [June 13, 2025, 4:03am UTC](https://forum.modular.com/t/trying-to-get-mojo-debugger-to-work-fully-on-non-ubuntu-systems/1635 "2025-06-13T04:03:59Z")
Hi all, I’m returning to Mojo after a little while away and on a new operating system that is not part of the Ubuntu family (it’s Open Mandriva). While I can get Mojo to run normally, the debugger is a different story. … --- ## [Segmentation fault (core dumped)](https://forum.modular.com/t/segmentation-fault-core-dumped/1592)
**Author:** [@notooth](https://forum.modular.com/u/notooth)\ **Replies:** 0\ **Last updated:** [June 5, 2025, 5:15pm UTC](https://forum.modular.com/t/segmentation-fault-core-dumped/1592 "2025-06-05T17:15:07Z")
This code caused Segmentation fault error. Can anyone help me fix it? struct State: var number: UInt256 var map1: Dict\[Int, UInt256\] var map2: Dict\[Int, UInt256\] var map3: Dict\[Int, UInt256\]… --- ## [How to emit full LLVM IR from Mojo source](https://forum.modular.com/t/how-to-emit-full-llvm-ir-from-mojo-source/1233)
**Author:** [@Yo-hey](https://forum.modular.com/u/Yo-hey)\ **Replies:** 14\ **Last updated:** [April 29, 2025, 4:25pm UTC](https://forum.modular.com/t/how-to-emit-full-llvm-ir-from-mojo-source/1233 "2025-04-29T16:25:12Z")
Hi, I’m looking for a way to emit the entire Mojo source file as LLVM IR. Currently, compile\_info() only exposes the LLVM IR for individual Mojo functions, but this is not sufficient for performing full optimization whe… --- ## [ONNX: difference in MAX cpu \<-\> gpu execution](https://forum.modular.com/t/onnx-difference-in-max-cpu-gpu-execution/1229)
**Author:** [@StrGenIx](https://forum.modular.com/u/StrGenIx)\ **Replies:** 2\ **Last updated:** [April 15, 2025, 2:36pm UTC](https://forum.modular.com/t/onnx-difference-in-max-cpu-gpu-execution/1229 "2025-04-15T14:36:27Z")
Hi all, I have been working towards using MAX to execute models stored in ONNX format by using max’s engine.load. I have a working version now, where I can load a model that was trained with Pytorch, exported to ONNX, … --- ## [LLVM intrinsic problem](https://forum.modular.com/t/llvm-intrinsic-problem/1144)
**Author:** [@eyeless77](https://forum.modular.com/u/eyeless77)\ **Replies:** 7\ **Last updated:** [April 4, 2025, 5:02am UTC](https://forum.modular.com/t/llvm-intrinsic-problem/1144 "2025-04-04T05:02:21Z")
Hi, when compiling my mojo projects I’m getting an error: And the piece of code causing it: @always\_inline fn pext(self, b: BitBoard) -\> UInt16: alias intrin = "llvm.x86.bmi.pext.64" return UI… --- ## [Pandas == condition fails](https://forum.modular.com/t/pandas-condition-fails/1189)
**Author:** [@letpat](https://forum.modular.com/u/letpat)\ **Replies:** 0\ **Last updated:** [April 1, 2025, 3:26pm UTC](https://forum.modular.com/t/pandas-condition-fails/1189 "2025-04-01T15:26:27Z")
pandas == condition fails environment magic 07.2 mojo 25.2.0 (26172dfe) pandas 2.2.3 pandas.mojo from python import Python def main(): pd = Python.import\_module("pandas") data = Python.dict() data\['col1'\] … --- ## [Question: vpermi2b inline assembly output incorrect in loop context due to register allocation](https://forum.modular.com/t/question-vpermi2b-inline-assembly-output-incorrect-in-loop-context-due-to-register-allocation/1091)
**Author:** [@Yo-hey](https://forum.modular.com/u/Yo-hey)\ **Replies:** 3\ **Last updated:** [March 24, 2025, 11:01am UTC](https://forum.modular.com/t/question-vpermi2b-inline-assembly-output-incorrect-in-loop-context-due-to-register-allocation/1091 "2025-03-24T11:01:24Z")
Hi all, I’m running into a register allocation issue when using inline assembly with vpermi2b. Here’s a minimal function that appears to work as intended when used in small, isolated cases: @always\_inline("nodebug") fn… --- ## [Cast numpy integer into Mojo integer](https://forum.modular.com/t/cast-numpy-integer-into-mojo-integer/670)
**Author:** [@ferdinand](https://forum.modular.com/u/ferdinand)\ **Replies:** 2\ **Last updated:** [March 7, 2025, 7:10pm UTC](https://forum.modular.com/t/cast-numpy-integer-into-mojo-integer/670 "2025-03-07T19:10:12Z")
I’m updating this little library I have going to 25.1, and am having a bit of trouble with casting from numpy types to Mojo types. Essentially I used to be able to cast numpy.uint8 to a Mojo Int as: py\_array\[rows\]\[colu… --- ## [How to convert for example Int8 to Int](https://forum.modular.com/t/how-to-convert-for-example-int8-to-int/611)
**Author:** [@notnot](https://forum.modular.com/u/notnot)\ **Replies:** 3\ **Last updated:** [February 24, 2025, 11:13pm UTC](https://forum.modular.com/t/how-to-convert-for-example-int8-to-int/611 "2025-02-24T23:13:09Z")
mojo 24.6.0 I’m trying to accomplish something very simple: var i8: Int8 = -1 i = Int(i8) this results in an error: error: no matching function in initialization So how to convert sized numerical types to Int or UIn… --- ## [When trying open-clip, getting "SmallVector unable to grow" internal error](https://forum.modular.com/t/when-trying-open-clip-getting-smallvector-unable-to-grow-internal-error/599)
**Author:** [@vladimir\_prus](https://forum.modular.com/u/vladimir_prus)\ **Replies:** 2\ **Last updated:** [February 21, 2025, 4:35am UTC](https://forum.modular.com/t/when-trying-open-clip-getting-smallvector-unable-to-grow-internal-error/599 "2025-02-21T04:35:14Z")
Hi, I am trying to run open-clip model using the ONNX format, and running into some internal error. The code is just this: from pathlib import Path import torch from datasets import load\_dataset from max import engin… --- ## [Compiler Error when compiling .mojo file into binary on Linux Mint](https://forum.modular.com/t/compiler-error-when-compiling-mojo-file-into-binary-on-linux-mint/518)
**Author:** [@jws325](https://forum.modular.com/u/jws325)\ **Replies:** 1\ **Last updated:** [February 4, 2025, 10:37am UTC](https://forum.modular.com/t/compiler-error-when-compiling-mojo-file-into-binary-on-linux-mint/518 "2025-02-04T10:37:42Z")
Hi, How do I fix this error on Linux Mint? I already have libstdc++6 Thanks. mojo build tinywm.mojo /usr/local/lib/gcc/x86\_64-pc-linux-gnu/6.3.0/…/…/…/…/x86\_64-pc-linux-gnu/bin/ld: /home/james/tinywm\_mojo/.magic/env… --- ## [Problems while passing function pointers to FFI](https://forum.modular.com/t/problems-while-passing-function-pointers-to-ffi/481)
**Author:** [@HammadHAB](https://forum.modular.com/u/HammadHAB)\ **Replies:** 0\ **Last updated:** [January 26, 2025, 5:42am UTC](https://forum.modular.com/t/problems-while-passing-function-pointers-to-ffi/481 "2025-01-26T05:42:43Z")
Hi. I am tyring to create library bindings of FLTK, in mojo. However, mojo’s compiler throws a segmentation fault when I try to pass an UnsafePointer of a function, to the ffi: from mjui.\_app import Application, FLTK\_WI… --- ## [Can't bitcast \`uint8\` SIMD vector to \`bool\`](https://forum.modular.com/t/cant-bitcast-uint8-simd-vector-to-bool/396)
**Author:** [@aditya](https://forum.modular.com/u/aditya)\ **Replies:** 2\ **Last updated:** [December 31, 2024, 1:47am UTC](https://forum.modular.com/t/cant-bitcast-uint8-simd-vector-to-bool/396 "2024-12-31T01:47:09Z")
This works: var tmp: SIMD\[DType.uint8, 8\] = SIMD\[DType.uint8, 8\](1, 1, 1, 1, 1, 1, 1, 1) var mask: SIMD\[DType.bool, 8\] = bitcast\[DType.bool\](tmp) But this doesn’t (mojo 25.1.0.dev2024121705 (67a9f701)): alias mask\_arr… --- ## [Installing Mojo via Magic on Ubuntu 22.04 LTS via WSL](https://forum.modular.com/t/installing-mojo-via-magic-on-ubuntu-22-04-lts-via-wsl/402)
**Author:** [@watson.shadd](https://forum.modular.com/u/watson.shadd)\ **Replies:** 1\ **Last updated:** [December 30, 2024, 6:00pm UTC](https://forum.modular.com/t/installing-mojo-via-magic-on-ubuntu-22-04-lts-via-wsl/402 "2024-12-30T18:00:55Z")
Hello, when I follow Get Started with Mojo instructions I am able to successfully complete Step 1 a and b below but then get stuck on part c. step 1. a. curl -ssL https://magic.modular.com/bfd2f286-11b1-4fee-bd2b-6be5b… [Next page](https://forum.modular.com/tag/debugging/1.md?match_all_tags=true&page=1&tags%5B%5D=debugging)