fine tune cmake find_package usage
diff --git a/cmake/zlib.cmake b/cmake/zlib.cmake
index e4c94f5..ed7c9c2 100644
--- a/cmake/zlib.cmake
+++ b/cmake/zlib.cmake
@@ -33,6 +33,12 @@
set(gRPC_INSTALL FALSE)
endif()
elseif("${gRPC_ZLIB_PROVIDER}" STREQUAL "package")
+ # zlib installation directory can be configured by setting ZLIB_ROOT
+ # We allow locating zlib using both "CONFIG" and "MODULE" as the expectation
+ # is that many Linux systems will have zlib installed via a distribution
+ # package ("MODULE"), while on Windows the user is likely to have installed
+ # zlib using cmake ("CONFIG").
+ # See https://cmake.org/cmake/help/v3.6/module/FindZLIB.html
find_package(ZLIB REQUIRED)
if(TARGET ZLIB::ZLIB)