# What is being cached in the stale compilation cache?

**URL:** <https://discourse.julialang.org/t/what-is-being-cached-in-the-stale-compilation-cache/49421>\
**Category:** Internals & Design\
**Created:** [November 1, 2020, 6:40pm UTC](https://discourse.julialang.org/t/what-is-being-cached-in-the-stale-compilation-cache/49421 "2020-11-01T18:40:06Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![oxinabox](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/oxinabox/32/206603_2.png) [@oxinabox](https://discourse.julialang.org/u/oxinabox)\
**Post date:** [November 1, 2020, 6:40pm UTC](https://discourse.julialang.org/t/what-is-being-cached-in-the-stale-compilation-cache/49421/1 "2020-11-01T18:40:06Z")

</div>

Julia used to do this a lot in 1.0, its mostly solved since 1.3 IIRC, because we have multiple caches.

```julia
[Info: Recompiling stale cache file /Users/oxinabox/.julia/compiled/v1.0/Revise/M1Qoh.ji for Revise [295af30f-e4ad-537b-8983-00126c2a3abe]

```

Is it JIT compilation of methods used?  
Or is it precompilation stuff?

---

<div class="post-metadata">

**Author:** ![kristoffer.carlsson](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/kristoffer.carlsson/32/22_2.png) [@kristoffer.carlsson](https://discourse.julialang.org/u/kristoffer.carlsson)\
**Post date:** [November 1, 2020, 6:43pm UTC](https://discourse.julialang.org/t/what-is-being-cached-in-the-stale-compilation-cache/49421/2 "2020-11-01T18:43:41Z")

</div>

From what I understand, it is lowered code and inference results.

From [Analyzing sources of compiler latency in Julia: method invalidations](https://julialang.org/blog/2020/08/invalidations/#can_and_should_this_be_fixed)

> For example, julia creates “precompile” ( `*.ji` ) files to speed up package usage. Currently, it saves type-inferred but not [native code](https://www.techopedia.com/definition/3846/native-code) to its precompile files.