further specifcy cmake

Author: cvanelteren

.github/workflows/build.yml

@@ -76,6 +76,9 @@ jobs:
             CPATH=/{project}/extern/include
             LIBRARY_PATH=/{project}/extern/lib
             LD_LIBRARY_PATH=/{project}/extern/lib
+            GEOS_LIBRARY=/{project}/extern/lib/libgeos.so
+            GEOS_INCLUDE_DIR=/{project}/extern/include
+            CMAKE_PREFIX_PATH=/{project}/extern
             SETUPTOOLS_USE_DISTUTILS=stdlib
           CIBW_TEST_COMMAND: >
             cd {project}