Error with stacked environments

[cossio]

I have setup a small example at https://github.com/cossio/JuliaStackedEnvFFMPEGIssue, of a package failing to load from an environment higher up the stack, due to it not finding required libraries. In the linked repo, there is a parent environment which has FFMPEG_jll installed. Then the error is triggered by trying to load FFMPEG_jll from the nested environment at the subdirectory child_env. However FFMPEG_jll loads fine if:

1. It is loaded from the parent environment.
2. It is installed as a direct dependency of the nested environment, and loaded there.

This issue originated from MakieOrg/Makie.jl#3123, since a similar error is occurring when attempting to load Makie. But it seems the source of the error is not Makie, but some underlying issue with dependency resolution in stacked environments.

julia> versioninfo()
Julia Version 1.9.3
Commit bed2cd540a1 (2023-08-24 14:43 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: macOS (arm64-apple-darwin22.4.0)
  CPU: 8 × Apple M2
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-14.0.6 (ORCJIT, apple-m1)
  Threads: 1 on 4 virtual cores
Environment:
  JULIA_EDITOR = mvim -R
  JULIA_PKG_USE_CLI_GIT = true
  JULIA_PKG_SERVER_REGISTRY_PREFERENCE = eager

Julia installed via juliaup.