CPack: fallback to v0.0.0-0 when git describe fails

When doing a shallow clone, the git repository may not have fetched any tag -
in which case `git describe --tags` will fail and in turn, cpack/CMakeLists.txt
will raise an error. This makes current CI builds fail.

As a temporary workaround, fallback to v0.0.0-0.

Signed-off-by: David Wagner <[email protected]>

Author: dawagner

cpack/CMakeLists.txt

@@ -34,8 +34,9 @@ execute_process(COMMAND git describe --tags --long
 
 set(REGEX "^v([0-9]+)\\.([0-9]+)\\.([0-9]+)-([0-9]+).*$")
 if(NOT "${GIT_DESCRIBE}" MATCHES "${REGEX}")
-    MESSAGE(SEND_ERROR "Could not parse git describe version \"${GIT_DESCRIBE}\" "
-                       "with regex \"${REGEX}\"")
+    message(WARNING "Could not parse git describe version \"${GIT_DESCRIBE}\" "
+        "with regex \"${REGEX}\". Falling back to 'v0.0.0-0'")
+    set(GIT_DESCRIBE "v0.0.0-0")
 endif()
 string(REGEX REPLACE "${REGEX}" "\\1" CPACK_PACKAGE_VERSION_MAJOR "${GIT_DESCRIBE}")
 string(REGEX REPLACE "${REGEX}" "\\2" CPACK_PACKAGE_VERSION_MINOR "${GIT_DESCRIBE}")