fix import Pkg into precompilation processes

Author: KristofferC

base/loading.jl

@@ -1066,6 +1066,7 @@ function create_expr_cache(input::String, output::String, concrete_deps::typeof(
     try
         write(in, """
         begin
+        import Pkg
         empty!(Base.LOAD_PATH)
         append!(Base.LOAD_PATH, $(repr(LOAD_PATH, :module => nothing)))
         empty!(Base.DEPOT_PATH)

base/sysimg.jl

@@ -563,6 +563,8 @@ Base.require(Base, :Pkg)
     @deprecate_binding REPLCompletions root_module(Base, :REPL).REPLCompletions true ", use `REPL.REPLCompletions` instead"
     @deprecate_binding Terminals       root_module(Base, :REPL).Terminals       true ", use `REPL.Terminals` instead"
 
+    @deprecate_binding(Pkg, root_module(Base, :Pkg), true, ", run `import Pkg` instead")
+
     @deprecate_stdlib readdlm  DelimitedFiles true
     @deprecate_stdlib writedlm DelimitedFiles true
     @deprecate_stdlib readcsv  DelimitedFiles true

stdlib/Pkg/test/pkg.jl

@@ -409,13 +409,13 @@ temp_pkg_dir() do
         touch(depsbuild)
         # Pkg.build works without the src directory now
         # but it's probably fine to require it.
-        msg = read(`$(Base.julia_cmd()) --startup-file=no -e 'redirect_stderr(STDOUT); using Logging; global_logger(SimpleLogger(STDOUT)); Pkg.build("BuildFail")'`, String)
+        msg = read(`$(Base.julia_cmd()) --startup-file=no -e 'redirect_stderr(STDOUT); using Logging; global_logger(SimpleLogger(STDOUT)); import Pkg; Pkg.build("BuildFail")'`, String)
         @test contains(msg, "Building BuildFail")
         @test !contains(msg, "Build failed for BuildFail")
         open(depsbuild, "w") do fd
             println(fd, "error(\"Throw build error\")")
         end
-        msg = read(`$(Base.julia_cmd()) --startup-file=no -e 'redirect_stderr(STDOUT); using Logging; global_logger(SimpleLogger(STDOUT)); Pkg.build("BuildFail")'`, String)
+        msg = read(`$(Base.julia_cmd()) --startup-file=no -e 'redirect_stderr(STDOUT); using Logging; global_logger(SimpleLogger(STDOUT)); import Pkg; Pkg.build("BuildFail")'`, String)
         @test contains(msg, "Building BuildFail")
         @test contains(msg, "Build failed for BuildFail")
         @test contains(msg, "Pkg.build(\"BuildFail\")")
@@ -426,7 +426,7 @@ temp_pkg_dir() do
     let package = "Example"
         Pkg.rm(package)  # Remove package if installed
         @test Pkg.installed(package) === nothing  # Registered with METADATA but not installed
-        msg = read(ignorestatus(`$(Base.julia_cmd()) --startup-file=no -e "redirect_stderr(STDOUT); using Logging; global_logger(SimpleLogger(STDOUT)); Pkg.build(\"$package\")"`), String)
+        msg = read(ignorestatus(`$(Base.julia_cmd()) --startup-file=no -e "redirect_stderr(STDOUT); using Logging; global_logger(SimpleLogger(STDOUT)); import Pkg; Pkg.build(\"$package\")"`), String)
         @test contains(msg, "$package is not an installed package")
         @test !contains(msg, "signal (15)")
     end
@@ -541,7 +541,7 @@ temp_pkg_dir() do
 
         Pkg.add(package)
         msg = read(ignorestatus(`$(Base.julia_cmd()) --startup-file=no -e
-            "redirect_stderr(STDOUT); using Logging; global_logger(SimpleLogger(STDOUT)); using Example; Pkg.update(\"$package\")"`), String)
+            "redirect_stderr(STDOUT); using Logging; global_logger(SimpleLogger(STDOUT)); using Example; import Pkg; Pkg.update(\"$package\")"`), String)
         @test contains(msg, Regex("- $package.*Restart Julia to use the updated versions","s"))
     end