# Distributed testing

**URL:** <https://discourse.julialang.org/t/distributed-testing/43824>\
**Category:** New to Julia\
**Created:** [July 28, 2020, 5:37pm UTC](https://discourse.julialang.org/t/distributed-testing/43824 "2020-07-28T17:37:37Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Peter\_Adelman](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/peter_adelman/32/11907_2.png) [@Peter\_Adelman](https://discourse.julialang.org/u/Peter_Adelman)\
**Post date:** [July 28, 2020, 5:37pm UTC](https://discourse.julialang.org/t/distributed-testing/43824/1 "2020-07-28T17:37:37Z")

</div>

I am developing a set of `]dev`’d packages. If I test them in serial, it takes about 2 hours.

I have been doing this instead:

```julia
# The script is intended to be run from `parent_dir/test`.
using Distributed
addproc(7)

@everywhere using Pkg
# It starts by activating the parent environment, which contains all the child packages
@everywhere Pkg.activate("..")

# It then tests them in parallel
packages = ["list","of","packages"]
tasks = Vector{Task}(undef, length(packages))
for (i, package) in enumerate(packages)
    tasks[i] = @spawnat :any Pkg.test(package; test_args=ARGS, coverage = "--coverage" in ARGS)
end

results = fetch.(tasks)

errs = [i for (i, val) in enumerate(results) if isa(val, RemoteException)]

if !isempty(errs)
    println("errors were throw, here is one:")
    throw.(res[errs])
end

```

It works in general, but sometimes it throws an error on a worker that it cannot find one of the locally `]dev`’d packages that definitely exists in the parent environment’s manifest. I can’t make a reproducible example of this that I can share externally, but it’s very repeatable internally.

Could this be some kind of collision of test environments? I’m under the impression that it’s generating a random name for the temp folder it uses, but ???.

Additionally, and possibly unrelatedly, it was much more reliable on Julia 1.3.1 and has become a real problem since this morning when I upgraded to 1.5.0-rc2

Edit: I got the tests to pass by setting the number of workers high enough that each Pkg.test call happened on a different worker.