Since "kernel.bbclass: run do_symlink_kernsrc before do_patch", kernel-source has not been generated if kernel package is set to externalsrc. tmp/work-shared/**/kernel-source/tools/spi: No such file or directory. Stop. The patch changed the dependency from do_configure to do_patch but do_patch is not existing if externalsrc is configured. The patch should be fixed for externalsrc awareness. [1]: https://patches.openembedded.org/series/25771/#
Ran out of time, moving to 4.2 and will consider backports
Bulk move of medium importance bugs from 5.1 to 5.2 on behalf of Bruce.