Can't complete the manual cmake build with correct gcc

[proton1k]

Describe the bug

Manual build process fails on version of GCC.

To Reproduce

1. Walk though the process described for manual build here (for Linux / Ubuntu)
2. Following the recommendations in an open issue here, find the file cmake/Hunter/config.cmake located where the Boost is: just use baseURL https://boostorg.jfrog.io/artifactory/main/release for the Boost v.1.66 archived files
3. complete the cmake step
4. attempt the cmake -build . which throws following:

$ cmake --build .
CMake Warning (dev) in CMakeLists.txt:
  No project() command is present.  The top-level CMakeLists.txt file must
  contain a literal, direct call to the project() command.  Add a line of
  code such as

    project(ProjectName)

  near the top of the file, but after cmake_minimum_required().

  CMake is pretending there is a "project(Project)" command on the first
  line.
This warning is for project developers.  Use -Wno-dev to suppress it.

-- The C compiler identification is GNU 7.5.0
-- The CXX compiler identification is GNU 7.5.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
CMake Error at CMakeLists.txt:16 (hunter_add_package):
  Unknown CMake command "hunter_add_package".


CMake Warning (dev) in CMakeLists.txt:
  No cmake_minimum_required command is present.  A line of code such as

    cmake_minimum_required(VERSION 3.16)

  should be added at the top of the file.  The version specified may be lower
  if you wish to support older CMake versions for this project.  For more
  information run "cmake --help-policy CMP0000".
This warning is for project developers.  Use -Wno-dev to suppress it.

-- Configuring incomplete, errors occurred!
See also "/home/username/ethminer/ethminer/CMakeFiles/CMakeOutput.log".

while the selected gcc and g++ versions are v.7. So it seems that version of the compiler should fit the requirement seen in the message, but since there's no other meaningful log, I do not understand what could be wrong.

Environment

• Operating System: Ubuntu 20.04
• Hardware
  00:01.0 VGA compatible controller: Red Hat, Inc. QXL paravirtual graphic card (rev 05)
  06:10.0 VGA compatible controller: NVIDIA Corporation GV100GL [Tesla V100 DGXS 32GB] (rev a1)
• Ethminer Version - latest
• Ethminer options used - non applicable

Additional context
Useful links I have walked through:

• recommended way to download a Boost v.1.66 here
• official documentation for the manual build described here
• few comments about incompatible gcc described here and the way to handle versions here
• useful comment regarding subversions here
• stackoverflow discussion regarding cmake Boost path here
• comments how to use flags to pass Boost path here or here what can be found in the source here

So what exactly do I miss ?