Use the asmjit and cpuinfo packages.

diff --git i/CMakeLists.txt w/CMakeLists.txt
index 73b043ac..703204dd 100644
--- i/CMakeLists.txt
+++ w/CMakeLists.txt
@@ -258,7 +258,7 @@ message(STATUS "CMAKE_CXX_FLAGS_DEBUG is ${CMAKE_CXX_FLAGS_DEBUG}")
 message(STATUS "CMAKE_CXX_FLAGS_RELEASE is ${CMAKE_CXX_FLAGS_RELEASE}")
 message(STATUS "==========")
 
-if(NOT TARGET asmjit)
+if(FALSE)
   # Download asmjit from github if ASMJIT_SRC_DIR is not specified.
   if(NOT DEFINED ASMJIT_SRC_DIR)
     set(ASMJIT_SRC_DIR "${FBGEMM_SOURCE_DIR}/external/asmjit"
@@ -291,7 +291,7 @@ if(NOT TARGET asmjit)
   endif()
 endif()
 
-if(NOT TARGET cpuinfo)
+if(FALSE)
   #Download cpuinfo from github if CPUINFO_SOURCE_DIR is not specified.
   if(NOT DEFINED CPUINFO_SOURCE_DIR)
     set(CPUINFO_SOURCE_DIR "${FBGEMM_SOURCE_DIR}/external/cpuinfo"
@@ -378,9 +378,12 @@ target_include_directories(fbgemm BEFORE
 target_link_libraries(fbgemm
   $<BUILD_INTERFACE:asmjit>
   $<BUILD_INTERFACE:cpuinfo>)
-add_dependencies(fbgemm
-  asmjit
-  cpuinfo)
+
+find_package(asmjit)
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(libcpuinfo REQUIRED IMPORTED_TARGET libcpuinfo)
+
+target_link_libraries(fbgemm asmjit::asmjit PkgConfig::libcpuinfo)
 
 if(OpenMP_FOUND)
   target_link_libraries(fbgemm OpenMP::OpenMP_CXX)
diff --git i/test/CMakeLists.txt w/test/CMakeLists.txt
index 1ddb2882..6e81c902 100644
--- i/test/CMakeLists.txt
+++ w/test/CMakeLists.txt
@@ -14,7 +14,7 @@ set(CMAKE_C_STANDARD 17)
 set(CMAKE_C_EXTENSIONS OFF)
 set(CMAKE_C_STANDARD_REQUIRED ON)
 
-if(FBGEMM_BUILD_TESTS AND NOT TARGET gtest)
+if(FALSE)
   #Download Googletest framework from github if
   #GOOGLETEST_SOURCE_DIR is not specified.
   if(NOT DEFINED GOOGLETEST_SOURCE_DIR)
@@ -78,7 +78,7 @@ macro(add_gtest TESTNAME)
     target_link_libraries(${TESTNAME} ${OpenMP_CXX_LIBRARIES})
   endif()
 
-  add_dependencies(${TESTNAME} gtest fbgemm)
+  add_dependencies(${TESTNAME} fbgemm)
   add_test(${TESTNAME} ${TESTNAME})
   set_target_properties(${TESTNAME} PROPERTIES FOLDER test)
 endmacro()