Fix some tests when run in base

Part of JuliaLang/julia#60058. When we don't
have a log file setup, the default IO is set to devnull. However, this
causes `Pkg.status` to early out and skip some validity checks that
we are testing for. Fix this by passing an appropriate io directly
to the API. For the REPL test, which don't have an IO argument,
override the global default IO, but to make that more robust also
switch it to a ScopedValue (which Pkg is already using elsewhere).

Author: Keno

ext/REPLExt/precompile.jl

@@ -14,25 +14,26 @@ let
         original_load_path = copy(LOAD_PATH)
         __init__()
         Pkg.UPDATED_REGISTRY_THIS_SESSION[] = true
-        Pkg.DEFAULT_IO[] = Pkg.unstableio(devnull)
-        withenv("JULIA_PKG_SERVER" => nothing, "JULIA_PKG_UNPACK_REGISTRY" => nothing) do
-            tmp = Pkg._run_precompilation_script_setup()
-            cd(tmp) do
-                try_prompt_pkg_add(Symbol[:notapackage])
-                promptf()
-                term = FakeTerminal()
-                repl = REPL.LineEditREPL(term, true)
-                REPL.run_repl(repl)
-                repl_init(repl)
+        @Base.ScopedValues.with Pkg.DEFAULT_IO => Pkg.unstableio(devnull) begin
+            withenv("JULIA_PKG_SERVER" => nothing, "JULIA_PKG_UNPACK_REGISTRY" => nothing) do
+                tmp = Pkg._run_precompilation_script_setup()
+                cd(tmp) do
+                    try_prompt_pkg_add(Symbol[:notapackage])
+                    promptf()
+                    term = FakeTerminal()
+                    repl = REPL.LineEditREPL(term, true)
+                    REPL.run_repl(repl)
+                    repl_init(repl)
+                end
             end
-        end
-        copy!(DEPOT_PATH, original_depot_path)
-        copy!(LOAD_PATH, original_load_path)
+            copy!(DEPOT_PATH, original_depot_path)
+            copy!(LOAD_PATH, original_load_path)
 
-        Base.precompile(Tuple{typeof(REPL.LineEdit.complete_line), REPLExt.PkgCompletionProvider, REPL.LineEdit.PromptState})
-        Base.precompile(Tuple{typeof(REPL.REPLCompletions.completion_text), REPL.REPLCompletions.PackageCompletion})
-        Base.precompile(Tuple{typeof(REPLExt.on_done), REPL.LineEdit.MIState, Base.GenericIOBuffer{Memory{UInt8}}, Bool, REPL.LineEditREPL})
-        return Base.precompile(Tuple{typeof(Core.kwcall), NamedTuple{(:hint,), Tuple{Bool}}, typeof(REPL.LineEdit.complete_line), REPLExt.PkgCompletionProvider, REPL.LineEdit.PromptState})
+            Base.precompile(Tuple{typeof(REPL.LineEdit.complete_line), REPLExt.PkgCompletionProvider, REPL.LineEdit.PromptState})
+            Base.precompile(Tuple{typeof(REPL.REPLCompletions.completion_text), REPL.REPLCompletions.PackageCompletion})
+            Base.precompile(Tuple{typeof(REPLExt.on_done), REPL.LineEdit.MIState, Base.GenericIOBuffer{Memory{UInt8}}, Bool, REPL.LineEditREPL})
+            return Base.precompile(Tuple{typeof(Core.kwcall), NamedTuple{(:hint,), Tuple{Bool}}, typeof(REPL.LineEdit.complete_line), REPLExt.PkgCompletionProvider, REPL.LineEdit.PromptState})
+        end
     end
 
     if Base.generating_output()

src/Pkg.jl

@@ -61,7 +61,7 @@ const UPDATED_REGISTRY_THIS_SESSION = Ref(false)
 const OFFLINE_MODE = Ref(false)
 const RESPECT_SYSIMAGE_VERSIONS = Ref(true)
 # For globally overriding in e.g. tests
-const DEFAULT_IO = Ref{Union{IO, Nothing}}(nothing)
+const DEFAULT_IO = Base.ScopedValues.ScopedValue{IO}()
 
 # ScopedValue to track whether we're currently in REPL mode
 const IN_REPL_MODE = Base.ScopedValues.ScopedValue{Bool}()
@@ -75,8 +75,8 @@ function unstableio(@nospecialize(io::IO))
         get(_io, :color, false) ? Base.ImmutableDict{Symbol, Any}(:color, true) : Base.ImmutableDict{Symbol, Any}()
     )
 end
-stderr_f() = something(DEFAULT_IO[], unstableio(stderr))
-stdout_f() = something(DEFAULT_IO[], unstableio(stdout))
+stderr_f() = something(Base.ScopedValues.get(DEFAULT_IO), unstableio(stderr))
+stdout_f() = something(Base.ScopedValues.get(DEFAULT_IO), unstableio(stdout))
 const PREV_ENV_PATH = Ref{String}("")
 
 usable_io(io) = (io isa Base.TTY) || (io isa IOContext{IO} && io.io isa Base.TTY)
@@ -1015,7 +1015,6 @@ end
 include("precompile.jl")
 
 # Reset globals that might have been mutated during precompilation.
-DEFAULT_IO[] = nothing
 Pkg.UPDATED_REGISTRY_THIS_SESSION[] = false
 PREV_ENV_PATH[] = ""
 Types.STDLIB[] = nothing