How to start and then terminate vlc in Swift 4?

Question

Swift

I'm trying to create an application that would allow you to record what is happening on the screen using vlc.
I found a handy line
/Applications/VLC.app/Contents/MacOS/VLC -I dummy screen:// --screen-fps=25 --quiet --sout "#transcode{vcodec=h264,vb072}:standard{access= file,mux=mp4,dst="Desktop/vlc-output-terminal.mp4"}"
which allows you to instantly start recording. Stop recording - ctrl+c.
All this works fine in the terminal. Now I want to pack into an application.
Found this:
https://iswift.org/cookbook/execute-a-shell-command
When I start I get
Couldn't posix_spawn: error 1

Here is the full text of the error

2018-12-31 18:12:28.583388+0300 CenLock[1857:91753] [General] An uncaught exception was raised
2018-12-31 18:12:28.583464+0300 CenLock[1857:91753] [General] Couldn't posix_spawn: error 1
2018-12-31 18:12:28.587944+0300 CenLock[1857:91753] [General] (
0 CoreFoundation 0x00007fff29d8d59b __exceptionPreprocess + 171
1 libobjc.A.dylib 0x00007fff510c0942 objc_exception_throw + 48
2 CoreFoundation 0x00007fff29e1d935 +[NSException raise:format:] + 197
3 Foundation 0x00007fff2c00c5c0 -[NSConcreteTask launchWithDictionary:error:] + 4486
4 CenLock 0x00000001000042b5 $S7CenLock11AppDelegateC14startRecordingyyypSgF + 293
5 CenLock 0x000000010000477c $S7CenLock11AppDelegateC14startRecordingyyypSgFTo + 188
6 AppKit 0x00007fff27a30a43 -[NSApplication(NSResponder) sendAction:to:from:] + 312
7 AppKit 0x00007fff274c5213 -[NSMenuItem _corePerformAction] + 323
8 AppKit 0x00007fff274c4f9b -[NSCarbonMenuImpl performActionWithHighlightingForItemAtIndex:] + 114
9 AppKit 0x00007fff2754ac7a -[NSMenu performActionForItemAtIndex:] + 133
10 AppKit 0x00007fff2754abe5 -[NSMenu _internalPerformActionForItemAtIndex:] + 94
11 AppKit 0x00007fff2754aa15 -[NSCarbonMenuImpl _carbonCommandProcessEvent:handlerCallRef:] + 106
12 AppKit 0x00007fff274112a2 NSSLMMenuEventHandler + 882
13 HIToolbox 0x00007fff28fc1904 _ZL23DispatchEventToHandlersP14EventTargetRecP14OpaqueEventRefP14HandlerCallRec + 1541
14 HIToolbox 0x00007fff28fc0c4d _ZL30SendEventToEventTargetInternalP14OpaqueEventRefP20OpaqueEventTargetRefP14HandlerCallRec + 374
15 HIToolbox 0x00007fff28fd5f21 SendEventToEventTarget + 39
16 HIToolbox 0x00007fff2901f3f9 _ZL18SendHICommandEventjPK9HICommandjjhPKvP20OpaqueEventTargetRefS5_PP14OpaqueEventRef + 411
17 HIToolbox 0x00007fff290482ee SendMenuCommandWithContextAndModifiers + 49
18 HIToolbox 0x00007fff290482aa SendMenuItemSelectedEvent + 188
19 HIToolbox 0x00007fff29048184 _ZL19FinishMenuSelectionP13SelectionDataP10MenuResultS2_ + 96
20 HIToolbox 0x00007fff2916087c _ZL19PopUpMenuSelectCoreP8MenuData5PointdS1_tjjPK4RecttjS4_S4_PK14__CFDictionaryPK10__CFStringPP13OpaqueMenuRefPt + 1662
21 HIToolbox 0x00007fff2915fcf7 _ZL26_HandlePopUpMenuSelection8P13OpaqueMenuRefP14OpaqueEventRefj5PointtjjPK4RecttS6_S6_PK14__CFDictionaryPK10__CFStringPS0_Pt + 409
22 HIToolbox 0x00007fff2902840c _HandlePopUpMenuSelectionWithDictionary + 268
23 AppKit 0x00007fff2754179a _NSSLMPopUpCarbonMenu3 + 5632
24 AppKit 0x00007fff275400f4 -[NSCarbonMenuImpl popUpMenu:atLocation:width:forView:withSelectedItem:withFont:withFlags:withOptions:] + 439
25 AppKit 0x00007fff27a1bc6b +[NSStatusBarButtonCell popupStatusBarMenu:inRect:ofView:withEvent:] + 1003
26 AppKit 0x00007fff27a1ad3a -[NSStatusBarButtonCell trackMouse:inRect:ofView:untilMouseUp:] + 159
27 AppKit 0x00007fff274d3670 -[NSControl mouseDown:] + 965
28 AppKit 0x00007fff27bcfd6d -[NSWindow(NSEventRouting) _handleMouseDownEvent:isDelayedEvent:] + 5891
29 AppKit 0x00007fff27bcc9c4 -[NSWindow(NSEventRouting) _reallySendEvent:isDelayedEvent:] + 2359
30 AppKit 0x00007fff27bcbc70 -[NSWindow(NSEventRouting) sendEvent:] + 497
31 AppKit 0x00007fff27a1e885 -[NSStatusBarWindow sendEvent:] + 348
32 AppKit 0x00007fff27a2d236 -[NSApplication(NSEvent) sendEvent:] + 2462
33 AppKit 0x00007fff2728d8b5 -[NSApplication run] + 812
34 AppKit 0x00007fff2725ca72 NSApplicationMain + 804
35 CenLock 0x000000010000a07d main + 13
36 libdyld.dylib 0x00007fff51cd7015 start + 1
)

I googled, but I couldn’t find any sensible explanation for macOS, or how to get around this business.
What is the difference between their example /usr/bin/env and /Applications/VLC.app/Contents/MacOS/VLC ?