diff --git a/base/boot.jl b/base/boot.jl
index a3c5c03bdf721e..fc00f571171c92 100644
--- a/base/boot.jl
+++ b/base/boot.jl
@@ -769,7 +769,7 @@ function is_top_bit_set(x::Union{Int8,UInt8})
 end
 
 # n.b. This function exists for CUDA to overload to configure error behavior (see #48097)
-throw_inexacterror(func::Symbol, to, val) = throw(InexactError(func, to, val))
+throw_inexacterror(args...) = throw(InexactError(args...))
 
 function check_sign_bit(::Type{To}, x) where {To}
     @inline
diff --git a/base/compiler/utilities.jl b/base/compiler/utilities.jl
index 1e002f8dad5a6d..00c4c9d4e3ec4e 100644
--- a/base/compiler/utilities.jl
+++ b/base/compiler/utilities.jl
@@ -498,6 +498,8 @@ end
 # options #
 ###########
 
+is_root_module(m::Module) = false
+
 inlining_enabled() = (JLOptions().can_inline == 1)
 
 function coverage_enabled(m::Module)
diff --git a/base/error.jl b/base/error.jl
index 07782fce5f52ea..fc294b3cb3eb04 100644
--- a/base/error.jl
+++ b/base/error.jl
@@ -228,15 +228,15 @@ macro assert(ex, msgs...)
         msg = Main.Base.string(msg)
     else
         # string() might not be defined during bootstrap
-        msg = :(_assert_tostring($(Expr(:quote,msg))))
+        msg = quote
+            msg = $(Expr(:quote,msg))
+            isdefined(Main, :Base) ? Main.Base.string(msg) :
+                (Core.println(msg); "Error during bootstrap. See stdout.")
+        end
     end
     return :($(esc(ex)) ? $(nothing) : throw(AssertionError($msg)))
 end
 
-# this may be overridden in contexts where `string(::Expr)` doesn't work
-_assert_tostring(msg) = isdefined(Main, :Base) ? Main.Base.string(msg) :
-    (Core.println(msg); "Error during bootstrap. See stdout.")
-
 struct ExponentialBackOff
     n::Int
     first_delay::Float64
diff --git a/base/errorshow.jl b/base/errorshow.jl
index b06052433ffc43..abc8083f38266e 100644
--- a/base/errorshow.jl
+++ b/base/errorshow.jl
@@ -400,7 +400,7 @@ end
 
 #Show an error by directly calling jl_printf.
 #Useful in Base submodule __init__ functions where stderr isn't defined yet.
-function showerror_nostdio(@nospecialize(err), msg::AbstractString)
+function showerror_nostdio(err, msg::AbstractString)
     stderr_stream = ccall(:jl_stderr_stream, Ptr{Cvoid}, ())
     ccall(:jl_printf, Cint, (Ptr{Cvoid},Cstring), stderr_stream, msg)
     ccall(:jl_printf, Cint, (Ptr{Cvoid},Cstring), stderr_stream, ":\n")
diff --git a/base/initdefs.jl b/base/initdefs.jl
index 2b2916fc804ade..56c2c0c5872728 100644
--- a/base/initdefs.jl
+++ b/base/initdefs.jl
@@ -9,7 +9,7 @@ A string containing the script name passed to Julia from the command line. Note
 script name remains unchanged from within included files. Alternatively see
 [`@__FILE__`](@ref).
 """
-global PROGRAM_FILE::String = ""
+global PROGRAM_FILE = ""
 
 """
     ARGS
@@ -480,7 +480,7 @@ end
 
 ## hook for disabling threaded libraries ##
 
-library_threading_enabled::Bool = true
+library_threading_enabled = true
 const disable_library_threading_hooks = []
 
 function at_disable_library_threading(f)
diff --git a/base/iostream.jl b/base/iostream.jl
index bea6612ebc220c..5d972945e00e0f 100644
--- a/base/iostream.jl
+++ b/base/iostream.jl
@@ -292,15 +292,12 @@ function open(fname::String; lock = true,
     if !lock
         s._dolock = false
     end
-    if ccall(:ios_file, Ptr{Cvoid},
-             (Ptr{UInt8}, Cstring, Cint, Cint, Cint, Cint),
-             s.ios, fname, flags.read, flags.write, flags.create, flags.truncate) == C_NULL
-        systemerror("opening file \"$fname\"")
-    end
+    systemerror("opening file $(repr(fname))",
+                ccall(:ios_file, Ptr{Cvoid},
+                      (Ptr{UInt8}, Cstring, Cint, Cint, Cint, Cint),
+                      s.ios, fname, flags.read, flags.write, flags.create, flags.truncate) == C_NULL)
     if flags.append
-        if ccall(:ios_seek_end, Int64, (Ptr{Cvoid},), s.ios) != 0
-            systemerror("seeking to end of file \"$fname\"")
-        end
+        systemerror("seeking to end of file $fname", ccall(:ios_seek_end, Int64, (Ptr{Cvoid},), s.ios) != 0)
     end
     return s
 end
diff --git a/base/libuv.jl b/base/libuv.jl
index 35424ad3eda3ed..66dfcfb3414ad1 100644
--- a/base/libuv.jl
+++ b/base/libuv.jl
@@ -134,9 +134,9 @@ function uv_asynccb end
 function uv_timercb end
 
 function reinit_stdio()
-    global stdin = init_stdio(ccall(:jl_stdin_stream, Ptr{Cvoid}, ()))::IO
-    global stdout = init_stdio(ccall(:jl_stdout_stream, Ptr{Cvoid}, ()))::IO
-    global stderr = init_stdio(ccall(:jl_stderr_stream, Ptr{Cvoid}, ()))::IO
+    global stdin = init_stdio(ccall(:jl_stdin_stream, Ptr{Cvoid}, ()))
+    global stdout = init_stdio(ccall(:jl_stdout_stream, Ptr{Cvoid}, ()))
+    global stderr = init_stdio(ccall(:jl_stderr_stream, Ptr{Cvoid}, ()))
     opts = JLOptions()
     if opts.color != 0
         have_color = (opts.color == 1)
diff --git a/base/loading.jl b/base/loading.jl
index 986efc1e1e5fbe..883e980b4000a2 100644
--- a/base/loading.jl
+++ b/base/loading.jl
@@ -2205,6 +2205,7 @@ const explicit_loaded_modules = Dict{PkgId,Module}()
 const loaded_modules_order = Vector{Module}()
 const module_keys = IdDict{Module,PkgId}() # the reverse
 
+is_root_module(m::Module) = @lock require_lock haskey(module_keys, m)
 root_module_key(m::Module) = @lock require_lock module_keys[m]
 
 @constprop :none function register_root_module(m::Module)
@@ -3415,9 +3416,9 @@ function check_clone_targets(clone_targets)
 end
 
 # Set by FileWatching.__init__()
-global mkpidlock_hook::Any
-global trymkpidlock_hook::Any
-global parse_pidfile_hook::Any
+global mkpidlock_hook
+global trymkpidlock_hook
+global parse_pidfile_hook
 
 # The preferences hash is only known after precompilation so just assume no preferences.
 # Also ignore the active project, which means that if all other conditions are equal,
diff --git a/base/reflection.jl b/base/reflection.jl
index 63909b4159877b..b1d41b4d68621d 100644
--- a/base/reflection.jl
+++ b/base/reflection.jl
@@ -20,8 +20,6 @@ Base
 """
 parentmodule(m::Module) = ccall(:jl_module_parent, Ref{Module}, (Any,), m)
 
-is_root_module(m::Module) = parentmodule(m) === m || (isdefined(Main, :Base) && m === Main.Base)
-
 """
     moduleroot(m::Module) -> Module
 
diff --git a/base/show.jl b/base/show.jl
index 8f52fefdd71520..f7846e316c3301 100644
--- a/base/show.jl
+++ b/base/show.jl
@@ -1056,7 +1056,7 @@ function show_type_name(io::IO, tn::Core.TypeName)
         # IOContext If :module is not set, default to Main (or current active module).
         # nothing can be used to force printing prefix
         from = get(io, :module, active_module())
-        if isdefined(tn, :module) && (from === nothing || !isvisible(sym, tn.module, from::Module))
+        if isdefined(tn, :module) && (from === nothing || !isvisible(sym, tn.module, from))
             show(io, tn.module)
             print(io, ".")
             if globfunc && !is_id_start_char(first(string(sym)))
diff --git a/base/threadingconstructs.jl b/base/threadingconstructs.jl
index acab7cf7b8299c..60aea04ddba645 100644
--- a/base/threadingconstructs.jl
+++ b/base/threadingconstructs.jl
@@ -79,7 +79,7 @@ function _sym_to_tpid(tp::Symbol)
     elseif tp == :foreign
         return Int8(-1)
     else
-        throw(ArgumentError("Unrecognized threadpool name `$tp`"))
+        throw(ArgumentError("Unrecognized threadpool name `$(repr(tp))`"))
     end
 end
 
diff --git a/stdlib/FileWatching/src/FileWatching.jl b/stdlib/FileWatching/src/FileWatching.jl
index 0c987ad01c828e..0ee572ec47d92c 100644
--- a/stdlib/FileWatching/src/FileWatching.jl
+++ b/stdlib/FileWatching/src/FileWatching.jl
@@ -468,11 +468,6 @@ function uv_fspollcb(handle::Ptr{Cvoid}, status::Int32, prev::Ptr, curr::Ptr)
     nothing
 end
 
-global uv_jl_pollcb::Ptr{Cvoid}
-global uv_jl_fspollcb::Ptr{Cvoid}
-global uv_jl_fseventscb_file::Ptr{Cvoid}
-global uv_jl_fseventscb_folder::Ptr{Cvoid}
-
 function __init__()
     global uv_jl_pollcb = @cfunction(uv_pollcb, Cvoid, (Ptr{Cvoid}, Cint, Cint))
     global uv_jl_fspollcb = @cfunction(uv_fspollcb, Cvoid, (Ptr{Cvoid}, Cint, Ptr{Cvoid}, Ptr{Cvoid}))
diff --git a/stdlib/LinearAlgebra/src/blas.jl b/stdlib/LinearAlgebra/src/blas.jl
index 413b7866c54448..8903aaddcc11bc 100644
--- a/stdlib/LinearAlgebra/src/blas.jl
+++ b/stdlib/LinearAlgebra/src/blas.jl
@@ -159,8 +159,9 @@ function check()
     interface = USE_BLAS64 ? :ilp64 : :lp64
     if !any(lib.interface == interface for lib in config.loaded_libs)
         interfacestr = uppercase(string(interface))
-        @error("No loaded BLAS libraries were built with $interfacestr support.")
-        exit(1)
+        @error("No loaded BLAS libraries were built with $(interfacestr) support")
+        println("Quitting.")
+        exit()
     end
 end