Format according to ocamlformat

  * Add a comment about printing pids without formatting

src/perf_tool_backend.ml

@@ -393,7 +393,9 @@ module Recording = struct
     in
     if debug_print_perf_commands then Core.printf "%s\n%!" (String.concat ~sep:" " argv);
     (* Perf prints output we don't care about and --quiet doesn't work for some reason *)
-    if debug_print_pid then Core.printf "Passed PIDs to perf: %s\n%!" (String.concat~sep:"" pid_opt);
+    if debug_print_pid
+    then Core.printf "Passed PIDs to perf: %s\n%!" (String.concat ~sep:"" pid_opt);
+    (* No need to format `pid_opt` again, since it already is a list of comma separated PIDs *)
     let perf_pid = perf_fork_exec ~env:perf_env ~prog:"perf" ~argv () in
     (* This detaches the perf process from our "process group" but not our session. This
      makes it so that when Ctrl-C is sent to magic_trace in the terminal to end an attach

src/trace.ml

@@ -77,7 +77,10 @@ let debug_print_perf_commands =
 
 let debug_print_pid =
   let open Command.Param in
-  flag "-z-print-pid" no_arg ~doc:"Prints the PIDs of the processes magic-trace attaches to."
+  flag
+    "-z-print-pid"
+    no_arg
+    ~doc:"Prints the PIDs of the processes magic-trace attaches to."
   |> debug_flag
 ;;
 
@@ -492,7 +495,14 @@ module Make_commands (Backend : Backend_intf.S) = struct
     return pid
   ;;
 
-  let attach_and_record record_opts ~elf ~debug_print_perf_commands ~debug_print_pid ~collection_mode pids =
+  let attach_and_record
+    record_opts
+    ~elf
+    ~debug_print_perf_commands
+    ~debug_print_pid
+    ~collection_mode
+    pids
+    =
     let%bind.Deferred.Or_error attachment =
       attach
         record_opts