move preference installation to later

Author: vchuravy

test/artifacts.jl

@@ -6,6 +6,13 @@ import Pkg.Artifacts: pack_platform!, unpack_platform, with_artifacts_directory,
 using TOML, Dates
 import Base: SHA1
 
+# Order-dependence in the tests, so we delay this until we need it
+if Base.find_package("Preferences") === nothing
+    @info "Installing Preferences for Pkg tests"
+    Pkg.add("Preferences") # Needed for sandbox and artifacts tests
+end
+using Preferences
+
 using ..Utils
 
 # Helper function to create an artifact, then chmod() the whole thing to 0o644.  This is
@@ -310,7 +317,6 @@ end
     end
 end
 
-using Preferences
 @testset "Artifact Usage" begin
     # Don't use `temp_pkg_dir()` here because we need `Pkg.test()` to run in the
     # same package context as the one we're running in right now.  Yes, this pollutes

test/runtests.jl

@@ -28,10 +28,6 @@ Pkg.REPLMode.minirepl[] = Pkg.REPLMode.MiniREPL() # re-set this given DEFAULT_IO
 
 include("utils.jl")
 
-if Base.find_package("Preferences") === nothing
-    Pkg.add("Preferences") # Needed for sandbox and artifacts tests
-end
-
 Logging.with_logger(hide_logs ? Logging.NullLogger() : Logging.current_logger()) do
     @testset "Pkg" begin
         @testset "$f" for f in [

test/sandbox.jl

@@ -1,6 +1,12 @@
 module SandboxTests
 import ..Pkg # ensure we are using the correct Pkg
 
+# Order-dependence in the tests, so we delay this until we need it
+if Base.find_package("Preferences") === nothing
+    @info "Installing Preferences for Pkg tests"
+    Pkg.add("Preferences") # Needed for sandbox and artifacts tests
+end
+
 using Test
 using UUIDs
 using Pkg