Fix building without git
If git isn't present, don't try to cache the
build configuration.
diff --git a/libtrellis/CMakeLists.txt b/libtrellis/CMakeLists.txt
index 05d41ba..540368e 100644
--- a/libtrellis/CMakeLists.txt
+++ b/libtrellis/CMakeLists.txt
@@ -58,6 +58,8 @@
find_package(Boost REQUIRED COMPONENTS ${boost_libs})
+find_package(Git)
+
include_directories(include/ ${Boost_INCLUDE_DIRS} ${PYTHON_INCLUDE_DIRS} 3rdparty/pybind11/include)
aux_source_directory(include/ INCLUDE_FILES)
@@ -113,7 +115,7 @@
if (EXISTS "${CMAKE_BINARY_DIR}/generated/last_git_version")
file(READ "${CMAKE_BINARY_DIR}/generated/last_git_version" LAST_GIT_VERSION)
endif()
-if (NOT ("${LAST_GIT_VERSION}" STREQUAL "${CURRENT_GIT_VERSION}"))
+if (NOT ("${LAST_GIT_VERSION}" STREQUAL "${CURRENT_GIT_VERSION}") OR NOT GIT_EXECUTABLE)
configure_file(
${CMAKE_SOURCE_DIR}/tools/version.cpp.in
${CMAKE_BINARY_DIR}/generated/version.cpp