Devtool was not designed with multiple sources in SRC_URI in mind and suffers from several limitations (non exhaustive list): * secondary sources not extracted into S are lost on devtool modify (see bug 15162: https://bugzilla.yoctoproject.org/show_bug.cgi?id=15162) * if case secondary sources is extracted in S it is not always possible to extract patches created buy the user with the correct "patchdir" parameter * for file://, that are not patch, if user modify the file and commit it the devtool source, devtool finish will update the local file AND create a new patch Most of these issue s may be solved by implementing a devtool unpack tracer (https://git.yoctoproject.org/poky/commit/?id=ef3e46afd910d4b7727d42c4c18b501525c65695. Using a devtool unpack tracer will also hopefully help to clean some part of devtool code