I found the bitbake pkg -c cleanall doesn't remove the related files in sysroots-components. And if I remove them manually, it won't restores again after bitbake pkg.
Works for me. bitbake gdk-pixbuf -ccleanall removes sysroots-components/corei7-64/gdk-pixbuf. If you can replicate, and be sure that you're not mixing up eg gdk-pixbuf with gdk-pixbuf-native (and thus the machine directory under sysroots-components) then please re-open with more details.
Thanks for reply. I found this problem on a project which has been successfully built once. I was trying to rebuild a recipe after source oe-init-build-env script in it. I create a new project and it's OK now. I'm not sure it's a issue or not.