Json: Logs are repeating while cmake

[saurabhbansal90]

• What is the issue you have?
  I am trying to use this library within my C++ project, so using the Embedded feature as described in README.
  I am cross-compiling it for AM437, and in the CMakeLists.txt, I have provided the path for compiler to be CMAKE_CXX_COMPILER arm-linux-gnueabihf-g++
  After adding the JSON library, it asked for the absolute path, so I provided that as CMAKE_CXX_COMPILER /usr/bin/arm-linux-gnueabihf-g++

But after this change, cmake .. is not getting completed and logs are repeating periodically as below:
`-- The C compiler identification is GNU 7.4.0
-- The CXX compiler identification is GNU 7.4.0
-- 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
-- Using the single-header code from /home/eternal/work/am437x_peripherals/json/single_include/
-- Configuring done
You have changed variables that require your cache to be deleted.
Configure will be re-run and you may have to reset some variables.
The following variables have changed:
CMAKE_CXX_COMPILER= /usr/bin/c++

-- The C compiler identification is GNU 7.4.0
-- The CXX compiler identification is GNU 7.4.0
-- 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
-- Using the single-header code from /home/eternal/work/am437x_peripherals/json/single_include/
-- Configuring done
You have changed variables that require your cache to be deleted.
Configure will be re-run and you may have to reset some variables.
The following variables have changed:
CMAKE_CXX_COMPILER= /usr/bin/c++

-- The C compiler identification is GNU 7.4.0
-- The CXX compiler identification is GNU 7.4.0
-- 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
^C
`

• Please describe the steps to reproduce the issue. Can you provide a small but working code example?
  The issue is appearing at the CMAKE level only, and I followed the procedure as defined in the Embedded section in README.

• What is the expected behavior?
  Logs are repeating and cmake itself is not getting completed

• And what is the actual behavior instead?
  cmake should get complete and I should be able to make to experiment with building JSON

• Which compiler and operating system are you using? Is it a supported compiler?
  We are using arm-linux-gnueabihf-g++.1 for our compilation

• Did you use a released version of the library or the version from the develop branch?
  It was develop branch

• If you experience a compilation error: can you compile and run the unit tests?

[nlohmann]

I am not sure whether this is really related to the library. In any case, I am not a CMake expert, so I hope someone can help.

[t-b]

@saurabhbansal90

Cmake is telling you

You have changed variables that require your cache to be deleted.
Configure will be re-run and you may have to reset some variables.
The following variables have changed:
CMAKE_CXX_COMPILER= /usr/bin/c++

so this is expected. Try with a clean build directory and set all cmake variables in one call. If it happens then again (which it shouldn't) please post the exact command.

[nlohmann]

@saurabhbansal90 Did https://github.com/nlohmann/json/issues/1809#issuecomment-545475617 fix the issue?

[Ghabry]

For reconfiguring CMake the typical solution is deleting CMakeCache.txt (and if this doesn't help also the folder CMakeFiles/) to prevent any side effects. That's a CMake problem that affects any project.

But the bug here seems to be that CMake runs into an endless loop which shouldn't happen.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.