Merge branch '1.4.x' into 1.5.x

spring-boot-docs/src/main/asciidoc/using-spring-boot.adoc

@@ -1135,6 +1135,15 @@ increase timeouts in your IDE. For example, in Eclipse you can select `Java` ->
 from `Preferences...` and change the `Debugger timeout (ms)` to a more suitable value
 (`60000` works well in most situations).
 
+WARNING: When using the remote debug tunnel with IntelliJ IDEA, all breakpoints must be
+configured to suspend the thread rather than the VM. By default, breakpoints in IntelliJ
+IDEA suspend the entire VM rather than only suspending the thread that hit the
+breakpoint. This has the unwanted side-effect of suspending the thread that manages the
+remote debug tunnel, causing your debugging session to freeze. When using the remote
+debug tunnel with IntelliJ IDEA, all breakpoints should be configured to suspend the
+thread rather than the VM. Please set
+https://youtrack.jetbrains.com/issue/IDEA-165769[IDEA-165769] for further details.
+
 
 
 [[using-boot-packaging-for-production]]