# How do I map a build ID to a cache file?

**URL:** <https://discourse.julialang.org/t/how-do-i-map-a-build-id-to-a-cache-file/61044>\
**Category:** General Usage\
**Tags:** precompilation\
**Created:** [May 12, 2021, 8:08pm UTC](https://discourse.julialang.org/t/how-do-i-map-a-build-id-to-a-cache-file/61044 "2021-05-12T20:08:25Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![bluesmoon](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bluesmoon/32/327_2.png) [@bluesmoon](https://discourse.julialang.org/u/bluesmoon)\
**Post date:** [May 12, 2021, 8:08pm UTC](https://discourse.julialang.org/t/how-do-i-map-a-build-id-to-a-cache-file/61044/1 "2021-05-12T20:08:25Z")

</div>

I’m using Julia 1.5.3

I have a module (`DSWB`) which depends on another module (`HTTP`), which in turn depends on another module (`MbedTLS@1.0.3`).

When I call `using DSWB` in my notebook, Julia tries to precompile, and then gives me a warning about `MbedTLS missing from the cache`:

```julia
┌ Info: Precompiling DSWB [52c15417-fbcb-4e40-ba2a-0ae41431db4f]
└ @ Base loading.jl:1278
┌ Warning: Module MbedTLS with build ID 7376940636683 is missing from the cache.
│ This may mean MbedTLS [739be429-bea8-5141-9913-cc70e7f3736d] does not support precompilation but is imported by a module that does.
└ @ Base loading.jl:1017

```

This only happens when running through a Jupyter notebook, and not when run via the REPL. In both cases, jupyter as well as the REPL are running as the same user.

My `kernel.json` file for Jupyter looks like this:

```julia
{
  "display_name": "Julia 1.5.3",
  "argv": [
    "/julia-1.5.3/bin/julia",
    "-i",
    "--color=yes",
    "/home/ubuntu/.julia/packages/IJulia/IDNmS/src/kernel.jl",
    "{connection_file}"
  ],
  "language": "julia",
  "env": {},
  "interrupt_mode": "signal"
}

```

How should I debug this issue?