Base.runtests: add environment variables for overriding the automat…

…ic networking detection (JuliaLang#43217)

test/choosetests.jl

@@ -164,16 +164,26 @@ function choosetests(choices = [])
  "download",
  ]
  net_on = true
- try
- ipa = getipaddr()
- catch
- if ci_option_passed
- @error("Networking unavailable, but `--ci` was passed")
- rethrow()
+ JULIA_TEST_NETWORKING_AVAILABLE = get(ENV, "JULIA_TEST_NETWORKING_AVAILABLE", "") |>
+ strip |>
+ lowercase |>
+ s -> tryparse(Bool, s) |>
+ x -> x === true
+ # If the `JULIA_TEST_NETWORKING_AVAILABLE` environment variable is set to `true`, we
+ # always set `net_on` to `true`.
+ # Otherwise, we set `net_on` to true if and only if networking is actually available.
+ if !JULIA_TEST_NETWORKING_AVAILABLE
+ try
+ ipa = getipaddr()
+ catch
+ if ci_option_passed
+ @error("Networking unavailable, but `--ci` was passed")
+ rethrow()
+ end
+ net_on = false
+ @warn "Networking unavailable: Skipping tests [" * join(net_required_for, ", ") * "]"
+ filter!(!in(net_required_for), tests)
  end
- net_on = false
- @warn "Networking unavailable: Skipping tests [" * join(net_required_for, ", ") * "]"
- filter!(!in(net_required_for), tests)
  end
 
  if ccall(:jl_running_on_valgrind,Cint,()) != 0 && "rounding" in tests

test/runtests.jl

@@ -102,7 +102,15 @@ cd(@__DIR__) do
  # * https://github.com/JuliaLang/julia/pull/29384
  # * https://github.com/JuliaLang/julia/pull/40348
  n = 1
- if net_on
+ JULIA_TEST_USE_MULTIPLE_WORKERS = get(ENV, "JULIA_TEST_USE_MULTIPLE_WORKERS", "") |>
+ strip |>
+ lowercase |>
+ s -> tryparse(Bool, s) |>
+ x -> x === true
+ # If the `JULIA_TEST_USE_MULTIPLE_WORKERS` environment variable is set to `true`, we use
+ # multiple worker processes regardless of the value of `net_on`.
+ # Otherwise, we use multiple worker processes if and only if `net_on` is true.
+ if net_on || JULIA_TEST_USE_MULTIPLE_WORKERS
  n = min(Sys.CPU_THREADS, length(tests))
  n > 1 && addprocs_with_testenv(n)
  LinearAlgebra.BLAS.set_num_threads(1)