cmake: fix default version if `git describe` fails

If the `git describe` command fails we want to fall back to a default
version.  _OBS_DEFAULT_VERSION is not in the same format as the string
returned by `git describe` though.  In the event that the command fails
just use _OBS_DEFAULT_VERSION directly rather than trying to parse it.

Fixes: cmake fails if git is not installed but .git/ exists #6940

cmake/Modules/VersionConfig.cmake

@@ -34,13 +34,15 @@ if(NOT DEFINED OBS_VERSION_OVERRIDE)
       RESULT_VARIABLE _OBS_VERSION_RESULT
       OUTPUT_STRIP_TRAILING_WHITESPACE)
 
-    if(NOT _OBS_VERSION_RESULT EQUAL 0)
+    if(_OBS_VERSION_RESULT EQUAL 0)
+      string(REPLACE "-" "." _CANONICAL_SPLIT ${_OBS_VERSION})
+      string(REPLACE "." ";" _CANONICAL_SPLIT ${_CANONICAL_SPLIT})
+      list(GET _CANONICAL_SPLIT 0 1 2 _OBS_VERSION_CANONICAL)
+      string(REPLACE "." ";" _OBS_VERSION ${_OBS_VERSION})
+    else()
       set(_OBS_VERSION "${_OBS_DEFAULT_VERSION}")
+      set(_OBS_VERSION_CANONICAL ${_OBS_DEFAULT_VERSION})
     endif()
-    string(REPLACE "-" "." _CANONICAL_SPLIT ${_OBS_VERSION})
-    string(REPLACE "." ";" _CANONICAL_SPLIT ${_CANONICAL_SPLIT})
-    list(GET _CANONICAL_SPLIT 0 1 2 _OBS_VERSION_CANONICAL)
-    string(REPLACE "." ";" _OBS_VERSION ${_OBS_VERSION})
   else()
     set(_OBS_VERSION ${_OBS_DEFAULT_VERSION})
     set(_OBS_VERSION_CANONICAL ${_OBS_DEFAULT_VERSION})