ld.lld: error: undefined symbol: __atomic_is_lock_free
>>> referenced by atomic_base.h:436 (/usr/lib/gcc/x86_64-pc-linux-gnu/11.2.1/include/g++-v11/bits/atomic_base.h:436)
>>>               CMakeFiles/watchman.dir/watchman/ChildProcess.cpp.o:(void folly::futures::detail::waitImpl<folly::SemiFuture<w_string>, w_string>(folly::SemiFuture<w_string>&))
>>> referenced by atomic_base.h:436 (/usr/lib/gcc/x86_64-pc-linux-gnu/11.2.1/include/g++-v11/bits/atomic_base.h:436)
>>>               CMakeFiles/watchman.dir/watchman/ChildProcess.cpp.o:(void folly::futures::detail::waitImpl<folly::SemiFuture<w_string>, w_string>(folly::SemiFuture<w_string>&))
>>> referenced by atomic_base.h:436 (/usr/lib/gcc/x86_64-pc-linux-gnu/11.2.1/include/g++-v11/bits/atomic_base.h:436)
>>>               CMakeFiles/watchman.dir/watchman/ChildProcess.cpp.o:(folly::futures::detail::WaitExecutor::WaitExecutor())

and
ld.lld: error: undefined symbol: __atomic_is_lock_free
>>> referenced by atomic_base.h:436 (/usr/lib/gcc/x86_64-pc-linux-gnu/11.2.1/include/g++-v11/bits/atomic_base.h:436)
>>>               CMakeFiles/cache.t.dir/watchman/test/CacheTest.cpp.o:(void folly::futures::detail::waitImpl<folly::SemiFuture<folly::Unit>, folly::Unit>(folly::SemiFuture<folly::Unit>&))
>>> referenced by atomic_base.h:436 (/usr/lib/gcc/x86_64-pc-linux-gnu/11.2.1/include/g++-v11/bits/atomic_base.h:436)
>>>               CMakeFiles/cache.t.dir/watchman/test/CacheTest.cpp.o:(void folly::futures::detail::waitImpl<folly::SemiFuture<folly::Unit>, folly::Unit>(folly::SemiFuture<folly::Unit>&))
>>> referenced by atomic_base.h:436 (/usr/lib/gcc/x86_64-pc-linux-gnu/11.2.1/include/g++-v11/bits/atomic_base.h:436)
>>>               CMakeFiles/cache.t.dir/watchman/test/CacheTest.cpp.o:(folly::futures::detail::WaitExecutor::WaitExecutor())
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -716,6 +716,7 @@ target_link_libraries(
   jansson
   wildmatch
   third_party_deps
+  atomic
 )
 
 if (WIN32)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -747,6 +747,7 @@ function(t_test NAME)
     ${NAME}.t
     testsupport wildmatch third_party_deps
     ${LIBGMOCK_LIBRARIES}
+    atomic
   )
   target_compile_definitions(${NAME}.t
     PUBLIC WATCHMAN_TEST_SRC_DIR=\"${CMAKE_CURRENT_SOURCE_DIR}\")