--verbose::
Pass --verbose to git-fetch and git-merge.
---[no-]recurse-submodules::
+--[no-]recurse-submodules[=yes|on-demand|no]::
This option controls if new commits of all populated submodules should
be fetched too (see linkgit:git-config[1] and linkgit:gitmodules[5]).
That might be necessary to get the data needed for merging submodule