git_describe conflict with esp idf framework

I added `etl` library as git submodule to my project and it builds normally for desktop.
But first attempt to build it for esp32 using esp idf framework failed with error about wrong arguments to git_describe. I realized then what I forgot to add 
```cmake
set(GIT_DIR_LOOKUP_POLICY ALLOW_LOOKING_ABOVE_CMAKE_SOURCE_DIR)
```
And error gone.

But there is no etl version in cmake logs.

After a short investigation I found etl's `git_describe` overriden by `espidf`'s version of it.

Here is esp idf's GetGitRevisionDescription.cmake file

```cmake
# - Returns a version string from Git
#
# These functions force a re-configure on each git commit so that you can
# trust the values of the variables in your build system.
#
#  get_git_head_revision(<refspecvar> <hashvar> <repo dir> [<additional arguments to git describe> ...])
#
# Returns the refspec and sha hash of the current head revision
#
#  git_describe(<var> <repo dir> [<additional arguments to git describe> ...])
#
# Returns the results of git describe on the source tree, and adjusting
# the output so that it tests false if an error occurs.
#
#  git_get_exact_tag(<var> <repo dir> [<additional arguments to git describe> ...])
#
# Returns the results of git describe --exact-match on the source tree,
# and adjusting the output so that it tests false if there was no exact
# matching tag.
#
# Requires CMake 2.6 or newer (uses the 'function' command)
#
# Original Author:
# 2009-2010 Ryan Pavlik <rpavlik@iastate.edu> <abiryan@ryand.net>
# http://academic.cleardefinition.com
# Iowa State University HCI Graduate Program/VRAC
#
# Copyright Iowa State University 2009-2010.
# Distributed under the Boost Software License, Version 1.0.
# (See accompanying file LICENSE_1_0.txt or copy at
# http://www.boost.org/LICENSE_1_0.txt)
#
# Updated 2018 Espressif Systems to add _repo_dir argument
# to get revision of other repositories

if(__get_git_revision_description)
    return()
endif()
set(__get_git_revision_description YES)

# We must run the following at "include" time, not at function call time,
# to find the path to this module rather than the path to a calling list file
get_filename_component(_gitdescmoddir ${CMAKE_CURRENT_LIST_FILE} PATH)

function(get_git_head_revision _refspecvar _hashvar _repo_dir)
    execute_process(COMMAND
        "${GIT_EXECUTABLE}"
        rev-parse
        --git-dir
        WORKING_DIRECTORY
        ${_repo_dir}
        RESULT_VARIABLE
        res
        OUTPUT_VARIABLE
        GIT_DIR
        ERROR_VARIABLE
        error
        OUTPUT_STRIP_TRAILING_WHITESPACE)

    if(NOT res EQUAL 0)
        string(STRIP "${error}" error)
        message(STATUS "git rev-parse returned '${error}'")
        return()
    endif()

    get_filename_component(GIT_DIR "${GIT_DIR}" ABSOLUTE BASE_DIR "${_repo_dir}")

    set(GIT_DATA "${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/git-data")
    if(NOT EXISTS "${GIT_DATA}")
        file(MAKE_DIRECTORY "${GIT_DATA}")
    endif()

    if(NOT EXISTS "${GIT_DIR}/HEAD")
        return()
    endif()

    set(HEAD_FILE "${GIT_DATA}/HEAD")
    configure_file("${GIT_DIR}/HEAD" "${HEAD_FILE}" COPYONLY)

    configure_file("${_gitdescmoddir}/GetGitRevisionDescription.cmake.in"
        "${GIT_DATA}/grabRef.cmake"
        @ONLY)
    include("${GIT_DATA}/grabRef.cmake")

    set(${_refspecvar} "${HEAD_REF}" PARENT_SCOPE)
    set(${_hashvar} "${HEAD_HASH}" PARENT_SCOPE)
endfunction()

function(git_describe _var _repo_dir)
    if(NOT GIT_FOUND)
        find_package(Git QUIET)
    endif()
    get_git_head_revision(refspec hash "${_repo_dir}")
    if(NOT GIT_FOUND)
        set(${_var} "GIT-NOTFOUND" PARENT_SCOPE)
        return()
    endif()
    if(NOT hash)
        set(${_var} "HEAD-HASH-NOTFOUND" PARENT_SCOPE)
        return()

    endif()

    # TODO sanitize
    #if((${ARGN}" MATCHES "&&") OR
    #	(ARGN MATCHES "||") OR
    #	(ARGN MATCHES "\\;"))
    #	message("Please report the following error to the project!")
    #	message(FATAL_ERROR "Looks like someone's doing something nefarious with git_describe! Passed arguments ${ARGN}")
    #endif()

    #message(STATUS "Arguments to execute_process: ${ARGN}")

    execute_process(COMMAND
        "${GIT_EXECUTABLE}"
        "-C"
        ${_repo_dir}
        describe
        "--always"
        "--tags"
        "--dirty"
        ${ARGN}
        WORKING_DIRECTORY
        "${CMAKE_CURRENT_SOURCE_DIR}"
        RESULT_VARIABLE
        res
        OUTPUT_VARIABLE
        out
        ERROR_VARIABLE
        error
        OUTPUT_STRIP_TRAILING_WHITESPACE)
    if(NOT res EQUAL 0)
        string(STRIP "${error}" error)
        message(STATUS "git describe returned '${error}'")
        set(out "${out}-${res}-NOTFOUND")
    endif()

    set(${_var} "${out}" PARENT_SCOPE)
endfunction()

function(git_get_exact_tag _var _repo_dir)
    git_describe(out "${_repo_dir}" --exact-match ${ARGN})
    set(${_var} "${out}" PARENT_SCOPE)
endfunction()
```

This variant has different git_describe arguments.

Does etl version used for something?
Should I search for a workaround for my project or it is ok?

[]