pull newest commits result in that the libzmq cannot cmake .. success.

[fengmao31]

Issue description

-- The C compiler identification is GNU 9.4.0
-- The CXX compiler identification is GNU 9.4.0
-- 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
-- Looking for pthread.h
-- Looking for pthread.h - found
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Failed
-- Looking for pthread_create in pthreads
-- Looking for pthread_create in pthreads - not found
-- Looking for pthread_create in pthread
-- Looking for pthread_create in pthread - found
-- Found Threads: TRUE  
CMake Error at CMakeLists.txt:29 (include):
  include could not find load file:

    TestZMQVersion

CMake Error at CMakeLists.txt:30 (include):
  include could not find load file:

    ZMQSourceRunChecks

CMake Error at CMakeLists.txt:31 (include):
  include could not find load file:

    ZMQSupportMacros

-- Found PkgConfig: /usr/bin/pkg-config (found version "0.29.1") 
-- Performing Test COMPILER_SUPPORTS_CXX11
-- Performing Test COMPILER_SUPPORTS_CXX11 - Success
-- Performing Test COMPILER_SUPPORTS_C11
-- Performing Test COMPILER_SUPPORTS_C11 - Success
-- Performing Test CXX_HAS_TAUT_WARNING
-- Performing Test CXX_HAS_TAUT_WARNING - Success
-- Performing Test CC_HAS_TAUT_WARNING
-- Performing Test CC_HAS_TAUT_WARNING - Success
-- Building draft classes and methods
-- Using radix tree implementation to manage subscriptions
-- Enable WebSocket transport
-- Could NOT find GnuTLS (missing: GNUTLS_LIBRARY GNUTLS_INCLUDE_DIR) (Required is at least version "3.6.7")
CMake Warning at CMakeLists.txt:212 (message):
  No WSS support, you may want to install GnuTLS and run cmake again

-- Using builtin sha1
-- Checking for module 'libbsd'
--   No package 'libbsd' found
-- Looking for strlcpy
-- Looking for strlcpy - not found
CMake Warning at CMakeLists.txt:266 (find_package):
  By not providing "Findsodium.cmake" in CMAKE_MODULE_PATH this project has
  asked CMake to find a package configuration file provided by "sodium", but
  CMake did not find one.

  Could not find a package configuration file provided by "sodium" with any
  of the following names:

    sodiumConfig.cmake
    sodium-config.cmake

  Add the installation prefix of "sodium" to CMAKE_PREFIX_PATH or set
  "sodium_DIR" to a directory containing one of the above files.  If "sodium"
  provides a separate development package or SDK, be sure it has been
  installed.

CMake Warning at CMakeLists.txt:280 (message):
  libsodium not installed, instead using builtin tweetnacl, you may want to
  install libsodium and run cmake again

-- Using tweetnacl for CURVE security
-- Looking for kqueue
-- Looking for kqueue - not found
-- Looking for epoll_create
-- Looking for epoll_create - found
-- Looking for epoll_create1
-- Looking for epoll_create1 - found
-- Using polling method in I/O threads: epoll
-- Using polling method in zmq_poll(er)_* API: poll
-- Looking for pselect
-- Looking for pselect - found
-- Using 64 bytes alignment for lock-free data structures
-- Looking for posix_memalign
-- Looking for posix_memalign - found
-- Looking for include file windows.h
-- Looking for include file windows.h - not found
-- Looking for include file condition_variable
-- Looking for include file condition_variable - found
-- Using condition_variable_t implementation: stl11
-- Looking for include file ifaddrs.h
-- Looking for include file ifaddrs.h - found
-- Looking for include file sys/uio.h
-- Looking for include file sys/uio.h - found
-- Looking for include file sys/eventfd.h
-- Looking for include file sys/eventfd.h - found
CMake Error at CMakeLists.txt:550 (zmq_check_efd_cloexec):
  Unknown CMake command "zmq_check_efd_cloexec".

-- Configuring incomplete, errors occurred!
See also "/home/fengmao/rima/libzmq/builds/CMakeFiles/CMakeOutput.log".
See also "/home/fengmao/rima/libzmq/builds/CMakeFiles/CMakeError.log".

Environment

• libzmq version (commit hash if unreleased):
• OS: ubuntu20

Minimal test code / Steps to reproduce the issue

pull newest commits and cmake ..

What's the actual result? (include assertion message & call stack if applicable)

libzmq cannot cmake .. success.

What's the expected result?

[fengmao31]

I shoud remove old version in the usr direction.