Merge branch 'jk/config-warn-on-inaccessible-paths'

When looking for $HOME/.gitconfig etc., it is OK if we cannot read them because they do not exist, but we did not diagnose existing files that we cannot read. * jk/config-warn-on-inaccessible-paths: warn_on_inaccessible(): a helper to warn on inaccessible paths attr: warn on inaccessible attribute files gitignore: report access errors of exclude files config: warn on inaccessible files