Compound 2 cpp applications one doesnt start

This is similar to issue #6431
My launch.json is pretty much the same however I see from the log that it is stuck at waiting for connection. One application always starts usually the first one listed in the compound. The issue is intermittent but happens most of the time, sometime changing any argument in launch.json helps mitigate the issue.

Version: 1.51.1 (user setup)
Commit: e5a624b788d92b8d34d1392e4c4d9789406efe8f
Date: 2020-11-10T23:34:32.027Z
Electron: 9.3.3
Chrome: 83.0.4103.122
Node.js: 12.14.1
V8: 8.3.110.13-electron.0
OS: Windows_NT x64 10.0.19041

Debug Console output from the application that fails to start:

--> E (output): {"type":"event","event":"output","body":{"category":"console","output":"1: (251) LaunchOptions{\"name\":\"rendezvous-commander\",\"type\":\"cppdbg\",\"request\":\"launch\",\"program\":\"/workspace/build/rendezvous/rendezvous_commander\",\"args\":[],\"stopAtEntry\":false,\"cwd\":\"/workspace/build\",\"environment\":[],\"externalConsole\":false,\"MIMode\":\"gdb\",\"logging\":{\"engineLogging\":true,\"trace\":true,\"traceResponse\":true},\"setupCommands\":[{\"description\":\"Enable pretty-printing for gdb\",\"text\":\"-enable-pretty-printing\",\"ignoreFailures\":true}],\"__configurationTarget\":5,\"__sessionId\":\"4fe2d8ad-757b-4b04-8ae3-49166ba6c40e\"}\n"},"seq":2}
1: (251) LaunchOptions{"name":"rendezvous-commander","type":"cppdbg","request":"launch","program":"/workspace/build/rendezvous/rendezvous_commander","args":[],"stopAtEntry":false,"cwd":"/workspace/build","environment":[],"externalConsole":false,"MIMode":"gdb","logging":{"engineLogging":true,"trace":true,"traceResponse":true},"setupCommands":[{"description":"Enable pretty-printing for gdb","text":"-enable-pretty-printing","ignoreFailures":true}],"__configurationTarget":5,"__sessionId":"4fe2d8ad-757b-4b04-8ae3-49166ba6c40e"}
--> E (output): {"type":"event","event":"output","body":{"category":"console","output":"1: (365) DbgCmd:echo $$ > /tmp/Microsoft-MIEngine-Pid-5mqlpb4m.6q4 ; cd \"/workspace/build/rendezvous\" ; DbgTerm=`tty` ; set -o monitor ; trap 'rm \"/tmp/Microsoft-MIEngine-In-q41whu8c.a7k\" \"/tmp/Microsoft-MIEngine-Out-88mxb8ba.369\" \"/tmp/Microsoft-MIEngine-Pid-5mqlpb4m.6q4\" \"/tmp/Microsoft-MIEngine-Cmd-ma8x2tc9.iwd\"' EXIT ; \"/usr/bin/gdb\" --interpreter=mi --tty=$DbgTerm < \"/tmp/Microsoft-MIEngine-In-q41whu8c.a7k\" > \"/tmp/Microsoft-MIEngine-Out-88mxb8ba.369\" & clear; pid=$! ; echo $pid > \"/tmp/Microsoft-MIEngine-Pid-5mqlpb4m.6q4\" ; wait $pid; \n"},"seq":4}
1: (365) DbgCmd:echo $$ > /tmp/Microsoft-MIEngine-Pid-5mqlpb4m.6q4 ; cd "/workspace/build/rendezvous" ; DbgTerm=`tty` ; set -o monitor ; trap 'rm "/tmp/Microsoft-MIEngine-In-q41whu8c.a7k" "/tmp/Microsoft-MIEngine-Out-88mxb8ba.369" "/tmp/Microsoft-MIEngine-Pid-5mqlpb4m.6q4" "/tmp/Microsoft-MIEngine-Cmd-ma8x2tc9.iwd"' EXIT ; "/usr/bin/gdb" --interpreter=mi --tty=$DbgTerm < "/tmp/Microsoft-MIEngine-In-q41whu8c.a7k" > "/tmp/Microsoft-MIEngine-Out-88mxb8ba.369" & clear; pid=$! ; echo $pid > "/tmp/Microsoft-MIEngine-Pid-5mqlpb4m.6q4" ; wait $pid; 
--> C (runInTerminal-6): {"type":"request","command":"runInTerminal","arguments":{"kind":"integrated","title":"cppdbg: rendezvous_commander","cwd":"","args":["/bin/sh","/tmp/Microsoft-MIEngine-Cmd-ma8x2tc9.iwd"],"env":{}},"seq":6}
--> E (output): {"type":"event","event":"output","body":{"category":"console","output":"1: (395) Wait for connection completion.\n"},"seq":8}
1: (395) Wait for connection completion.

Start with the compound launch configuration described in the issue and reproduce the intermittent failure using the Debug Console output, especially the “Wait for connection completion” point. Compare the two applications’ launch behavior and use issue #6431 as related context; done means both C++ applications start reliably in the compound configuration.