Package set-up not propagating to workers with Distributed


$ julia --version
julia version 1.6.0
$ lscpu
~/root/MyPackage$ lscpu
Architecture:                    x86_64
CPU op-mode(s):                  32-bit, 64-bit
Byte Order:                      Little Endian
Address sizes:                   39 bits physical, 48 bits virtual
CPU(s):                          4
On-line CPU(s) list:             0-3
Thread(s) per core:              1
Core(s) per socket:              4
Socket(s):                       1
NUMA node(s):                    1
Vendor ID:                       GenuineIntel
CPU family:                      6
Model:                           158
Model name:                      Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz

Say I want the following package structure, and want to use ReTest’s parallel testing (my issue appears to be with how code-loading works in Distributed, so this isn’t really a ReTest-specific issue).

| root/
    | MyPackage/
        | Project.toml
        | Manifest.toml
        | src/
            | MyPackage.jl
        | test/
            | runtests.jl
            | MyPackageTests.jl

I initialised this package in the following way:

$ cd root && julia
(...) pkg> generate MyPackage;
$ cd MyPackage && julia
(...) pkg> activate .
(...) pkg> instantiate
(...) pkg> add ReTest InlineTest Distributed;

Fill in MyPackage.jl, runtests.jl, and MyPackageTests.jl with some Julia code.
Not too important what that code is - although I am following the guide from here in ReTest.

Then to set up:

$ julia
(...) pkg> activate .
(...) pkg> instantiate
(MyPackage) pkg> st
     Project MyPackage v0.1.0
      Status `~/root/MyPackage/Project.toml`
  [bd334432] InlineTest v0.2.0
  [e0db7c4e] ReTest v0.3.2
  [8ba89e20] Distributed
julia> LOAD_PATH
3-element Vector{String}:
 "@"        # Should be current active environment for MyPackage
 "@v#.#"    # Should be @v1.6 on my system
 "@stdlib"  # Should be absolute path of current Julia installation's stdlib
julia> # Should this code be in .jl files? Don't think that should matter.
julia> using Distributed
julia> addprocs(2)
julia> @everywhere include("test/MyPackageTests.jl")
ERROR: On worker 2:
LoadError: ArgumentError: Package MyPackage not found in current path:
- Run `import Pkg; Pkg.add("MyPackage")` to install the MyPackage package.

 [1] require
   @ ./loading.jl:871
 [2] include
   @ ./client.jl:444
 [3] top-level scope
   @ none:1
 [4] eval
   @ ./boot.jl:360
 [5] #103
   @ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.6/Distributed/src/process_messages.jl:274
 [6] run_work_thunk
   @ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.6/Distributed/src/process_messages.jl:63
 [7] run_work_thunk
   @ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.6/Distributed/src/process_messages.jl:72
 [8] #96
   @ ./task.jl:406
in expression starting at /path/to/root/MyPackage/test/MyPackageTests.jl:1

...and 2 more exceptions.

 [1] sync_end(c::Channel{Any})
   @ Base ./task.jl:364
 [2] macro expansion
   @ ./task.jl:383 [inlined]
 [3] remotecall_eval(m::Module, procs::Vector{Int64}, ex::Expr)
   @ Distributed /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.6/Distributed/src/macros.jl:223
 [4] top-level scope
   @ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.6/Distributed/src/macros.jl:207

I’d like to understand why this is. On GitHub I see this issue that was supposedly fixed. I can confirm when I run that example that I also get the exact same problem as above with MyPackage.

Before filing a bug or opening an issue there, I’d like to check here in case this is a process problem on my part. If not, there’s evidently something wrong with Distributed/ReTest and I’ll open tickets for those. Any help much appreciated.