In file launch.json (you should change the values of "target" and "gdbpath", to remove the hardcoded absolute paths that will change for each user grabbing your project from GIT or other, and instead replace with the substitute path keys that VSStudio provides so other users won't have a conflict). See update launch.json file to see how it should be.
{
"version": "0.2.0",
"configurations": [
{
"type": "gdb",
"request": "launch",
"cwd": "${workspaceRoot}",
"name": "PlatformIO Debugger",
"target": "${workspaceFolder}/.pioenvs/lpc1768/firmware.elf",
"gdbpath": "${env:USERPROFILE}/.platformio/penv/Scripts/piodebuggdb",
"autorun": [ "source .pioinit" ]
}
]
}