"vfs" in git version string breaks cmake git version parser

[alexfeinman]

• [ X ] I was not able to find an open or closed issue matching what I'm seeing

Setup

64-bit git on Ubuntu 18.04 64 bit

$ git --version --build-options

git version 2.29.0.vfs.0.0
cpu: x86_64
built from commit: 3c7b47771c6afc8e8093f066fe29ff80fcf0b8ac
sizeof-long: 8
sizeof-size_t: 8
shell-path: /bin/sh

• Which version of Windows are you running? Vista, 7, 8, 10? Is it 32-bit or 64-bit?

$ cmd.exe /c ver

Ubuntu Linux - using this git build with Scalar

• What options did you set as part of the installation? Or did you choose the
  defaults?

# One of the following:
> type "C:\Program Files\Git\etc\install-options.txt"
> type "C:\Program Files (x86)\Git\etc\install-options.txt"
> type "%USERPROFILE%\AppData\Local\Programs\Git\etc\install-options.txt"
$ cat /etc/install-options.txt

N/A

• Any other interesting things about your environment that might be related
  to the issue you're seeing?

Details

• Which terminal/shell are you running Git from? e.g Bash/CMD/PowerShell/other

bash

• What commands did you run to trigger this issue? If you can provide a
  Minimal, Complete, and Verifiable example
  this will help us understand the issue.

git clone 
https://github.com/leggedrobotics/SimBenchmark
cd SimBenchmark/lib
mkdir build
cd build
cmake ..

• What did you expect to occur after running these commands?

cmake run successfully completes

• What actually happened instead?

CMake Error at /usr/share/cmake-3.19/Modules/ExternalProject.cmake:2449 (message):
error: git version 1.6.5 or later required for --recursive flag with 'git
submodule ...': GIT_VERSION_STRING=''

• If the problem was occurring with a specific repository, can you provide the
  URL to that repository to help us with testing?

https://github.com/leggedrobotics/SimBenchmark

[derrickstolee]

Hi @alexfeinman, I imagine that this also fails with Git for Windows, which includes windows in this spot? Or is there special logic in CMake to handle that option?

In general, it would be preferable if CMake could update their version parsing to allow extra arbitrary data after the first three numbers, but I'm not sure how to make that happen.