# Julia hangs on \`using PProf\`

**URL:** <https://discourse.julialang.org/t/julia-hangs-on-using-pprof/102646>\
**Category:** Profiling\
**Created:** [August 9, 2023, 4:17pm UTC](https://discourse.julialang.org/t/julia-hangs-on-using-pprof/102646 "2023-08-09T16:17:26Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Larbino1](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/larbino1/32/37831_2.png) [@Larbino1](https://discourse.julialang.org/u/Larbino1)\
**Post date:** [August 9, 2023, 4:17pm UTC](https://discourse.julialang.org/t/julia-hangs-on-using-pprof/102646/1 "2023-08-09T16:17:26Z")

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I’m trying to do some allocation profiling.

I start a thread, which is reading from a pipe, and I want to check that it is not allocating.

Then, I do `using PProf` and julia hangs.

If I do using PProf before starting this thread, it does not hang.

What is causing this?

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<div class="post-metadata">

**Author:** ![Larbino1](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/larbino1/32/37831_2.png) [@Larbino1](https://discourse.julialang.org/u/Larbino1)\
**Post date:** [August 9, 2023, 4:26pm UTC](https://discourse.julialang.org/t/julia-hangs-on-using-pprof/102646/2 "2023-08-09T16:26:19Z")

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Done a little more investigation - probably more to do with what’s going in the thread than with PProf.

It seems to be causing other things to hang as well