--- Libc/Libc-1725.40.4/gen/backtrace.3
+++ Libc/Libc-1353.100.2/gen/backtrace.3
@@ -66,12 +66,6 @@
 .Fa "void** array"
 .Fa "int size"
 .Fc
-.Ft size_t
-.Fo backtrace_async
-.Fa "void** array"
-.Fa "size_t size"
-.Fa "uint32_t* task_id"
-.Fc
 .Sh DESCRIPTION
 These routines provide a mechanism to examine the current thread's call stack.
 .Pp
@@ -119,27 +113,6 @@
 .Pp
 .Fn backtrace_from_fp
 takes a backtrace of frames starting from the given frame pointer.
-.Pp
-.Fn backtrace_async
-behaves exactly like
-.Fn backtrace
-unless it is invoked from a Swift async context.  In that case, instead of
-writing the return addresses of the OS call stack, the continuation addresses
-of the async invocations that led to the current state are provided.  If
-unwinding an async stack rather than an OS stack, the value pointed to by
-.Fa task_id
-will be set to a non-zero identifier that for the current process uniquely
-identifies the async task currently running.  Otherwise, 0 is stored.
-.Pp
-Note that the continuation addresses provided by
-.Fn backtrace_async
-have an offset of 1 added to them.  Most symbolication engines will substract
-1 from the call stack return addresses in order to symbolicate the call site
-rather than the return location.  With a Swift async continuation, substracting
-1 from its address would result in an address in a different function.  This
-offset allows the returned addresses to be handled correctly by most existing
-symbolication engines.
-.Pp
 .Sh EXAMPLE
 .Pp
     #include <execinfo.h>
@@ -164,8 +137,6 @@
 and
 .Fn backtrace_from_fp
 first appeared macOS 10.14 and iOS 12.
-.Fn backtrace_async
-first appeared in macOS 12.
 .Sh SEE ALSO
 .Xr dladdr 3 ,
 .Xr malloc 3