Implications of failed PPStack test

[ndusek]

I am trying to install RCall and the following test is failing:

Test Failed at /home/ndusek/.julia/packages/RCall/Wyd74/test/runtests.jl:65
  Expression: unsafe_load(cglobal((:R_PPStackTop, RCall.libR), Int)) == 0
   Evaluated: 8589934592 == 0

I see in the runtests.jl file that this test is only for non-conda-installed R on Linux (as mentioned in #462):

if !Sys.iswindows() # https://github.com/JuliaInterop/RCall.jl/pull/462
    if !RCall.conda_provided_r # this test will fail for the Conda-provided R
        @test unsafe_load(cglobal((:R_PPStackTop, RCall.libR), Int)) == 0
    end
end

Can someone explain to me:

• What is the above testing for?
• What is the implication of a failed test?

Apologies if this is all common knowledge. I have quite a bit of experience with R, but not at this low of a level, and I have no experience with Julia.

For reference, I'm running:

• RCall version: 0.13.14
• Julia version: 1.8.3
• R version: 4.2.2 (running in rocker/geospatial:4.2.2 container)