python3Packages.dm-tree: Fix build

diff --git a/tree/CMakeLists.txt b/tree/CMakeLists.txt

index 8f9946c..b9d6e9b 100644

index 4fd1b1a..f0d072b 100644

--- a/tree/CMakeLists.txt

+++ b/tree/CMakeLists.txt

@@ -50,70 +50,80 @@ if(APPLE)

@@ -50,70 +50,79 @@ if(APPLE)

   set (CMAKE_FIND_FRAMEWORK LAST)

 endif()

-# Fetch pybind to be able to use pybind11_add_module symbol.

-set(PYBIND_VER v2.6.2)

-set(PYBIND_VER v2.10.1)

-include(FetchContent)

-FetchContent_Declare(

-  pybind11

+

+if (NOT pybind11_FOUND)

+  # Fetch pybind to be able to use pybind11_add_module symbol.

+  set(PYBIND_VER v2.6.2)

+  set(PYBIND_VER v2.10.1)

+  include(FetchContent)

+  FetchContent_Declare(

+    pybind11

 # Define pybind11 tree module.

 pybind11_add_module(_tree tree.h tree.cc)

-add_dependencies(_tree abseil-cpp)

-if (WIN32 OR MSVC)

-    set(ABSEIL_LIB_PREF "absl")

-    set(LIB_SUFF "lib")

-

+find_package(absl)

+

+if (NOT absl_FOUND)

+      set(LIB_SUFF "a")

+  endif()

+

-if (WIN32 OR MSVC)

-    set(ABSEIL_LIB_PREF "absl")

-    set(LIB_SUFF "lib")

+  # Link abseil static libs.

+  # We don't use find_library here to force cmake to build abseil before linking.

+  set(ABSEIL_LIBS int128 raw_hash_set raw_logging_internal strings throw_delegate)