GDB commands often fail with 'No symbol "someSymbol" in current context.'

Type: Debugger

Describe the bug

• OS and Version: Debian 9
• VS Code Version: 1.43.2
• C/C++ Extension Version: 27.0
• Other extensions you installed (and if the issue persists after disabling them): None
• A clear and concise description of what the bug is.

When debugging I find that when I first try to execute a gdb command with -exec, I get the error 'No symbol "someSymbol" in current context.' even though that variable is clearly in scope. If I hover over the variable or execute a non-gdb command first, and then execute the gdb command, that fixes the problem.

I attached a small repro where I can reproduce the problem by doing the following:

1. Add a breakpoint inside Widget::doStuff
2. Start debugging and switch away from the "Run/Debug" view before hitting the breakpoint. Go to the explorer view, for example.
3. After hitting the breakpoint, try running '-exec p a' in the debug console and note that it doesn't work
4. Switch back to the "Run/Debug" view and execute a gdb command. It works now.

This reproduces very frequently when trying to debug our project at work. I noticed that it happens most often when trying to print a member variable from within a method. Local variables often work. I attached the log output after following the above repro steps on my work example.

log.txt
repro.zip

Compile the repro with g++ -g main.cpp and debug with the following launch.json:

    {
        "name": "Debug Repro",
        "type": "cppdbg",
        "request": "launch",
        "program": "${workspaceFolder}/a.out",
        "args": [],
        "stopAtEntry": false,
        "cwd": "${workspaceFolder}",
        "environment": [],
        "externalConsole": false,
        "MIMode": "gdb",
        "setupCommands": [
            {
                "description": "Enable pretty-printing for gdb",
                "text": "-enable-pretty-printing",
                "ignoreFailures": true
            }
        ],
        "miDebuggerPath": "/usr/bin/gdb"
    }