Build Configuration:
BB_VERSION        = "1.15.3"
TARGET_ARCH       = "i586"
TARGET_OS         = "linux"
MACHINE           = "sys940x"
DISTRO            = "poky"
DISTRO_VERSION    = "1.2+snapshot-20120924"
TUNE_FEATURES     = "m32 core2"
TARGET_FPU        = ""
meta-yocto        = "master:88429f018bbb15749f31067d5e7bf33c21b15f92"
meta-sys940x      
meta-intel        = "dvhart/1.3/fri2:102814d8ba2735d1e24c75b297508f863da9915e"
meta              = "master:88429f018bbb15749f31067d5e7bf33c21b15f92"

While updating sys940x from linux-yocto 3.2 to 3.4, the core-image-sato do_rootfs task would fail with:

| ++ ls /build/poky/master/sys940x_AdM_pj/tmp/pkgdata/sys940x-poky-linux/runtime-reverse/kernel-module-ipv6
| + filename=/build/poky/master/sys940x_AdM_pj/tmp/pkgdata/sys940x-poky-linux/runtime-reverse/kernel-module-ipv6
| ++ sed -n 's/^PN: //p' /build/poky/master/sys940x_AdM_pj/tmp/pkgdata/sys940x-poky-linux/runtime-reverse/kernel-module-ipv6
| sed: can't read /build/poky/master/sys940x_AdM_pj/tmp/pkgdata/sys940x-poky-linux/runtime-reverse/kernel-module-ipv6: No such file or directory


In linux-yocto 3.4 CONFIG_IPV6=y, in 3.2 CONFIG_IPV6=m. The do_rootfs task found the runtime-reverse/kernel-module-ipv6 link from the previous linux-yocto-rt 3.2 build, while the 3.4 build didn't add or remove the link, but it also didn't install the target the link was pointing to in ../runtime.

The warning:
bb.warn("The recipe is trying to install files into a shared area when those files already exist. Those files are:\n   %s" % "\n   ".join(match))

Didn't trigger. I suspect this is because it is looking for files that are being overwritten, as opposed to files which are left over from a previous kernel build and are NOT being recreated.

A clean of the previous kernel gets things building again. This can be confusing if the PREFERRED_PROVIDER has moved from the previous version to the new version as the wrong package will get cleaned.