do it in a different way

base/REPL.jl

@@ -111,12 +111,13 @@ function ip_matches_func(ip, func::Symbol)
 end
 
 function display_error(io::IO, er, bt)
+    print_with_color(:red, io, "ERROR: ")
     # remove REPL-related frames from interactive printing
     eval_ind = findlast(addr->Base.REPL.ip_matches_func(addr, :eval), bt)
     if eval_ind != 0
         bt = bt[1:eval_ind-1]
     end
-    showerror(IOContext(io, :REPLError => true), er, bt)
+    showerror(IOContext(io, :hascolor => true), er, bt)
 end
 
 immutable REPLDisplay{R<:AbstractREPL} <: Display

base/client.jl

@@ -63,8 +63,8 @@ warn_color()   = repl_color("JULIA_WARN_COLOR", default_color_warn)
 info_color()   = repl_color("JULIA_INFO_COLOR", default_color_info)
 input_color()  = text_colors[repl_color("JULIA_INPUT_COLOR", default_color_input)]
 answer_color() = text_colors[repl_color("JULIA_ANSWER_COLOR", default_color_answer)]
-bt_linfo_color()   = repl_color("JULIA_BT_LINFO_COLOR", :bold)
-bt_funcdef_color() = repl_color("JULIA_BT_FUNCTION_COLOR", :bold)
+stackframe_linfo_color() =    repl_color("JULIA_STACKFRAME_LINFO_COLOR", :bold)
+stackframe_function_color() = repl_color("JULIA_STACKFRAME_FUNCTION_COLOR", :bold)
 
 function repl_cmd(cmd, out)
     shell = shell_split(get(ENV,"JULIA_SHELL",get(ENV,"SHELL","/bin/sh")))

base/replutil.jl

@@ -193,25 +193,13 @@ function showerror(io::IO, ex::TypeError)
 end
 
 function showerror(io::IO, ex, bt; backtrace=true)
-   try
-        Base.with_output_color(:red, io) do io
+    try
+        with_output_color(get(io, :hascolor, false) ? :red : :nothing, io) do io
             showerror(io, ex)
         end
     finally
         if backtrace
-            if get(io, :REPLError, false)
-                buffer_bt = IOBuffer()
-                show_backtrace(IOContext(buffer_bt, io), bt)
-                bt_str = takebuf_string(buffer_bt)
-                if !isempty(bt_str)
-                    print(io, "\nStacktrace:")
-                    print(io, bt_str)
-                end
-            else
-                Base.with_output_color(:red, io) do io
-                    show_backtrace(io, bt)
-                end
-            end
+            show_backtrace(io, bt)
         end
     end
 end
@@ -575,28 +563,22 @@ function show_method_candidates(io::IO, ex::MethodError, kwargs::Vector=Any[])
     end
 end
 
-function show_trace_entry(io, frame, n)
-    !get(io, :REPLError, false) && println(io)
-    show(io, frame, full_path=true)
+function show_trace_entry(io, frame, n; prefix = " in ")
+    print(io, "\n")
+    show(io, frame, full_path=true; prefix = prefix)
     n > 1 && print(io, " (repeats ", n, " times)")
 end
 
 function show_backtrace(io::IO, t::Vector)
-    if get(io, :REPLError, false)
-        n_frames = 0
-        stack_counter = 0
-        process_backtrace((a,b) -> n_frames += 1, t)
-        process_entry = (last_frame, n) -> begin
-            println(io)
-            stack_counter += 1
-            n_spaces_align = ndigits(n_frames) - ndigits(stack_counter) + 1
-            print(io, " "^n_spaces_align, "[", stack_counter, "]", )
-            show_trace_entry(io, last_frame, n)
-        end
-    else
-        process_entry = (last_frame, n) -> show_trace_entry(io, last_frame, n)
+    n_frames = 0
+    frame_counter = 0
+    process_backtrace((a,b) -> n_frames += 1, t)
+    n_frames != 0 && print(io, "\n\nStacktrace:")
+    process_entry = (last_frame, n) -> begin
+        frame_counter += 1
+        n_spaces_align = ndigits(n_frames) - ndigits(frame_counter) + 1
+        show_trace_entry(io, last_frame, n, prefix = string(" "^n_spaces_align, "[", frame_counter, "] "))
     end
-
     process_backtrace(process_entry, t)
 end
 

base/show.jl

@@ -1028,10 +1028,9 @@ end
 
 function show_lambda_types(io::IO, li::Core.MethodInstance)
     # print a method signature tuple for a lambda definition
-    isreplerror = get(io, :REPLError, false)
     local sig
     returned_from_do = false
-    Base.with_output_color(isreplerror ? Base.bt_funcdef_color() : :nothing, io) do io
+    Base.with_output_color(get(io, :hascolor, false) ? stackframe_function_color() : :nothing, io) do io
         if li.specTypes === Tuple
             print(io, li.def.name, "(...)")
             returned_from_do = true
@@ -1052,7 +1051,7 @@ function show_lambda_types(io::IO, li::Core.MethodInstance)
     end
     returned_from_do && return
     first = true
-    print_style = isreplerror ? :bold : :nothing
+    print_style = get(io, :hascolor, false) ? :bold : :nothing
     print_with_color(print_style, io, "(")
     for i = 2:length(sig)  # fixme (iter): `eachindex` with offset?
         first || print(io, ", ")

base/stacktraces.jl

@@ -188,7 +188,7 @@ function show_spec_linfo(io::IO, frame::StackFrame)
         if frame.func === empty_sym
             @printf(io, "ip:%#x", frame.pointer)
         else
-            print_with_color(get(io, :REPLError, false) ? Base.bt_funcdef_color() : :nothing, io, string(frame.func))
+            print_with_color(get(io, :hascolor, false) ? Base.stackframe_function_color() : :nothing, io, string(frame.func))
         end
     else
         linfo = get(frame.linfo)
@@ -200,14 +200,14 @@ function show_spec_linfo(io::IO, frame::StackFrame)
     end
 end
 
-function show(io::IO, frame::StackFrame; full_path::Bool=false)
-    isreplerror = get(io, :REPLError, false)
-    print(io, isreplerror ? " ─ " : " in ")
+function show(io::IO, frame::StackFrame; full_path::Bool=false,
+              prefix = " in ")
+    print(io, prefix)
     show_spec_linfo(io, frame)
     if frame.file !== empty_sym
         file_info = full_path ? string(frame.file) : basename(string(frame.file))
         print(io, " at ")
-        Base.with_output_color(isreplerror ? Base.bt_linfo_color() : :nothing, io) do io
+        Base.with_output_color(get(io, :hascolor, false) ? Base.stackframe_linfo_color() : :nothing, io) do io
             print(io, file_info, ":")
             if frame.line >= 0
                 print(io, frame.line)

doc/manual/interacting-with-julia.rst

@@ -311,5 +311,5 @@ informational messages in cyan you can add the following to your ``juliarc.jl``
 
 The backtrace that is printed in the REPL when an error is thrown can also be customized. The color of the function name and the file and line info for each stack frame can be changed with environment variables as::
 
-    ENV["JULIA_BT_FUNCTION_COLOR"] = :green # Color of function names
-    ENV["JULIA_BT_LINFO_COLOR"] = :yellow # Color of file name and line number
+    ENV["JULIA_STACKFRAME_FUNCTION_COLOR"] = :green # Color of function names
+    ENV["JULIA_STACKFRAME_LINFO_COLOR"] = :yellow # Color of file name and line number