xcode - Swift Playground not showing errors -

i beginning swift , using tutorials in swift playgrounds macos.

so example code be

var str = "hello, playground" str str1 

i not red error information on str 1. crash in console

playground execution failed: error: myplayground.playground:1:1:  error: use of unresolved identifier 'str1' str1 ^~~~   * thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1    * frame #0: 0x0000000102157360 com.apple.dt.xcode.playgroundstub-macosx`executeplayground      frame #1: 0x000000010215522a com.apple.dt.xcode.playgroundstub-macosx`-[playgroundviewbridgeservice execute] + 90 

if correct code playground refresh , show new data not reporting errors

how stop xcode crashing , behave documented?

xcode version 8.3 (8e162) macos 10.12.4

i've tried deleting xcode files (including ones creates during build) , reinstalling , using different user

actually playground show "red mark error on left side of code" , there's automatic option fix error, regular projects.

i had same problem (red marks wasn't showing on left). solved me:

1. right click error on issue navigator (top left panel)
2. on menu > open > quick look
3. then same command again , open > playground page

i'm on xcode 8.3.2

update: same valid xcode 9.0