Use version.txt if present (eg. when it's a source code archive)

CMakeLists.txt

@@ -1,16 +1,34 @@
 cmake_minimum_required (VERSION 3.20)
 
+set(PROJECT_NAME libreweb-browser)
+
 option(DOXYGEN "Build Doxygen documentation" ON)
 option(UNITTEST "Build unit tests")
 option(PACKAGE "Build packages in release mode" OFF)
 set(CMAKE_OSX_DEPLOYMENT_TARGET "11.0" CACHE STRING "Minimum macOS deployment version")
 
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake")
 
-include(GitVersion)
+# If we have a git folder, get GIT_TAG_VERSION from most recent git tag
+if(EXISTS "${CMAKE_SOURCE_DIR}/.git")
+  include(GitVersion)
+  set(LOCAL_PROJECT_VERSION ${GIT_TAG_VERSION})
+else()
+  # In source archives there is no .git folder present.
+  # If CUSTOM_PROJECT_VERSION is defined use it as version.
+  if(DEFINED CUSTOM_PROJECT_VERSION)
+      set(LOCAL_PROJECT_VERSION "${CUSTOM_PROJECT_VERSION}")
+  elseif(EXISTS "${CMAKE_SOURCE_DIR}/version.txt")
+    # Read version from version.txt file
+    file(READ "version.txt" LOCAL_PROJECT_VERSION)
+  else()
+    # Fallback to version 1.0.0
+    set(LOCAL_PROJECT_VERSION "1.0.0")
+  endif()
+endif()
 
-project(libreweb-browser
-  VERSION ${GIT_TAG_VERSION}
+project({PROJECT_NAME}
+  VERSION ${LOCAL_PROJECT_VERSION}
   DESCRIPTION "LibreWeb Browser - Decentralized Web-Browser"
   LANGUAGES C CXX)