replace global logger in init()

src/init.jl

@@ -116,6 +116,11 @@ function init(args)
     end
     redirect_stdin(IJuliaStdio(stdin,"stdin"))
 
+    if isdefined(Base, :CoreLogging)
+        logger = Base.CoreLogging.SimpleLogger(Base.stderr)
+        Base.CoreLogging.global_logger(logger)
+    end
+
     send_status("starting")
     global inited = true
 end

src/stdio.jl

@@ -32,15 +32,6 @@ for s in ("stdout", "stderr", "stdin")
     @eval function Base.$f(io::IJuliaStdio)
         io[:jupyter_stream] != $s && throw(ArgumentError(string("expecting ", $s, " stream")))
         if isdefined(Base, :stdout)
-            # On Julia 0.7, we need to override the global logger as well
-            logger = Base.CoreLogging._global_logstate.logger
-
-            # Override logging if it's pointing at the default stderr
-            if logger.stream == Base.stderr
-                new_logstate = Base.CoreLogging.LogState(typeof(logger)(io, logger.min_level))
-                Core.eval(Base.CoreLogging, Expr(:(=), :(_global_logstate), new_logstate))
-            end
-
             Core.eval(Base, Expr(:(=), $sq, io))
         else
             # On Julia 0.6-, the variables are called Base.STDIO, not Base.stdio