only print show(err) suggestion for limited types in REPL

fixes #50575

Author: JeffBezanson

base/errorshow.jl

@@ -772,9 +772,6 @@ function show_backtrace(io::IO, t::Vector)
     if haskey(io, :last_shown_line_infos)
         empty!(io[:last_shown_line_infos])
     end
-    # this will be set to true if types in the stacktrace are truncated
-    limitflag = Ref(false)
-    io = IOContext(io, :stacktrace_types_limited => limitflag)
 
     # t is a pre-processed backtrace (ref #12856)
     if t isa Vector{Any}
@@ -800,9 +797,6 @@ function show_backtrace(io::IO, t::Vector)
         # process_backtrace returns a Vector{Tuple{Frame, Int}}
         show_full_backtrace(io, filtered; print_linebreaks = stacktrace_linebreaks())
     end
-    if limitflag[]
-        print(io, "\nSome type information was truncated. Use `show(err)` to see complete types.")
-    end
     nothing
 end
 

stdlib/REPL/src/REPL.jl

@@ -283,6 +283,19 @@ function print_response(repl::AbstractREPL, response, show_value::Bool, have_col
     end
     return nothing
 end
+
+function repl_display_error(errio::IO, @nospecialize errval)
+    # this will be set to true if types in the stacktrace are truncated
+    limitflag = Ref(false)
+    errio = IOContext(errio, :stacktrace_types_limited => limitflag)
+    Base.invokelatest(Base.display_error, errio, errval)
+    if limitflag[]
+        print(errio, "Some type information was truncated. Use `show(err)` to see complete types.")
+        println(errio)
+    end
+    return nothing
+end
+
 function print_response(errio::IO, response, show_value::Bool, have_color::Bool, specialdisplay::Union{AbstractDisplay,Nothing}=nothing)
     Base.sigatomic_begin()
     val, iserr = response
@@ -292,7 +305,7 @@ function print_response(errio::IO, response, show_value::Bool, have_color::Bool,
             if iserr
                 val = Base.scrub_repl_backtrace(val)
                 Base.istrivialerror(val) || setglobal!(Base.MainInclude, :err, val)
-                Base.invokelatest(Base.display_error, errio, val)
+                repl_display_error(errio, val)
             else
                 if val !== nothing && show_value
                     try
@@ -315,7 +328,7 @@ function print_response(errio::IO, response, show_value::Bool, have_color::Bool,
                 try
                     excs = Base.scrub_repl_backtrace(current_exceptions())
                     setglobal!(Base.MainInclude, :err, excs)
-                    Base.invokelatest(Base.display_error, errio, excs)
+                    repl_display_error(errio, excs)
                 catch e
                     # at this point, only print the name of the type as a Symbol to
                     # minimize the possibility of further errors.

stdlib/REPL/test/repl.jl

@@ -1659,3 +1659,14 @@ fake_repl() do stdin_write, stdout_read, repl
     write(stdin_write, '\x04')
     Base.wait(repltask)
 end
+
+fake_repl() do stdin_write, stdout_read, repl
+    backend = REPL.REPLBackend()
+    repltask = @async REPL.run_repl(repl; backend)
+    write(stdin_write,
+          "a = UInt8(81):UInt8(160); b = view(a, 1:64); c = reshape(b, (8, 8)); d = reinterpret(reshape, Float64, c); sqrteach(a) = [sqrt(x) for x in a]; sqrteach(d)\n\"ZZZZZ\"\n")
+    txt = readuntil(stdout_read, "ZZZZZ")
+    write(stdin_write, '\x04')
+    wait(repltask)
+    @test contains(txt, "Some type information was truncated. Use `show(err)` to see complete types.")
+end

test/stacktraces.jl

@@ -235,7 +235,6 @@ struct F49231{a,b,c,d,e,f,g} end
         stacktrace(catch_backtrace())
     end
     str = sprint(Base.show_backtrace, st, context = (:limit=>true, :color=>true, :displaysize=>(50,105)))
-    @test endswith(str, "to see complete types.")
     @test contains(str, "[5] \e[0m\e[1mcollect_to!\e[22m\e[0m\e[1m(\e[22m\e[90mdest\e[39m::\e[0mVector\e[90m{…}\e[39m, \e[90mitr\e[39m::\e[0mBase.Generator\e[90m{…}\e[39m, \e[90moffs\e[39m::\e[0m$Int, \e[90mst\e[39m::\e[0mTuple\e[90m{…}\e[39m\e[0m\e[1m)\e[22m\n\e[90m")
 
     st = try