i am completely new to use cmake. i am facing an issue with debugging the following error.

Obseved:

CMake Error at CMakeLists.txt:15 (find_package):
  find_package called with incorrect number of arguments


-- Using CATKIN_DEVEL_PREFIX: /home/guo/ws4/devel
-- Using CMAKE_PREFIX_PATH: /opt/ros/noetic
-- This workspace overlays: /opt/ros/noetic
-- Found PythonInterp: /usr/bin/python3 (found suitable version "3.8.10", minimum required is "3") 
-- Using PYTHON_EXECUTABLE: /usr/bin/python3
-- Using Debian Python package layout
-- Found PY_em: /usr/lib/python3/dist-packages/em.py  
-- Using empy: /usr/lib/python3/dist-packages/em.py
-- Using CATKIN_ENABLE_TESTING: ON
-- Call enable_testing()
-- Using CATKIN_TEST_RESULTS_DIR: /home/guo/ws4/build/test_results
-- Forcing gtest/gmock from source, though one was otherwise available.
-- Found gtest sources under '/usr/src/googletest': gtests will be built
-- Found gmock sources under '/usr/src/googletest': gmock will be built
CMake Deprecation Warning at /usr/src/googletest/CMakeLists.txt:4 (cmake_minimum_required):
  Compatibility with CMake < 2.8.12 will be removed from a future version of
  CMake.

  Update the VERSION argument <min> value or use a ...<max> suffix to tell
  CMake that the project does not need compatibility with older versions.


CMake Deprecation Warning at /usr/src/googletest/googlemock/CMakeLists.txt:45 (cmake_minimum_required):
  Compatibility with CMake < 2.8.12 will be removed from a future version of
  CMake.

  Update the VERSION argument <min> value or use a ...<max> suffix to tell
  CMake that the project does not need compatibility with older versions.


CMake Deprecation Warning at /usr/src/googletest/googletest/CMakeLists.txt:56 (cmake_minimum_required):
  Compatibility with CMake < 2.8.12 will be removed from a future version of
  CMake.

  Update the VERSION argument <min> value or use a ...<max> suffix to tell
  CMake that the project does not need compatibility with older versions.


-- Found PythonInterp: /usr/bin/python3 (found version "3.8.10") 
-- Found Threads: TRUE  
-- Using Python nosetests: /usr/bin/nosetests3
-- catkin 0.8.10
-- BUILD_SHARED_LIBS is on
-- BUILD_SHARED_LIBS is on
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- ~~  traversing 1 packages in topological order:
-- ~~  - multi_lidar_calibration
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- +++ processing catkin package: 'multi_lidar_calibration'
-- ==> add_subdirectory(multi_lidar_calibration)
-- Using these message generators: gencpp;geneus;genlisp;gennodejs;genpy
-- Found PkgConfig: /usr/bin/pkg-config (found version "0.29.1") 
-- Checking for module 'yaml-cpp'
--   Found yaml-cpp, version 0.6.2
-- Installing devel-space wrapper /home/guo/ws4/src/multi_lidar_calibration/scripts/cloud_crop_helper.py to /home/guo/ws4/devel/lib/multi_lidar_calibration
-- Configuring incomplete, errors occurred!
See also "/home/guo/ws4/build/CMakeFiles/CMakeOutput.log".
See also "/home/guo/ws4/build/CMakeFiles/CMakeError.log".
Invoking "cmake" failed

CMakeLists:

cmake_minimum_required(VERSION 2.8 FATAL_ERROR)

project(TFAC-master)

set(CMAKE_BUILD_TYPE Release) 
find_package(PCL 1.7 REQUIRED)


link_directories(${PCL_LIBRARY_DIRS})
add_definitions(${PCL_DEFINITIONS})

include_directories(${PCL_INCLUDE_DIRS} include)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")

FILE(GLOB SRCS src/*.cpp)


add_executable (TFAC-master ${SRCS})
target_link_libraries (TFAC-master ${PCL_LIBRARIES})

Kindly help me in resolving the issue.

This would be the first thing to fix. Line 15 in your example code is a blank line and the only find_package looks OK. Can you provide the context up to this line 15 that made this output?