I believe I found a bug in libjpeg-turbo_8d+1.3.1.bb recipe, located in meta-openembedded/meta-oe/recipes-core/jpeg (well, I'm observing its effects, I'll better not provide any guess of patch). The thing is that when I install toolchain from script generated by `bitbake -c populate_sdk myimage`, where myimage inherits core-image and my layer conf file specifies (PREFERRED_PROVIDER_jpeg = "libjpeg-turbo") and (PREFERRED_PROVIDER_jpeg-native = "libjpeg-turbo-native"), libjpeg and libturbojpeg binaries are located in /opt/poky/1.7.1/sysroots/armv7a-vfp-neon-poky-linux-gnueabi/usr/lib, but libturbojpeg.so link is missing. Hence when trying to build my application which links -lturbojpeg, linker fails. The temp directory tmp/work/armv7a-vfp-neon-poky-linux-gnueabi/libjpeg-turbo/8d+1.3.1-r0/image/usr/lib contains the file, it is just not propagated into the sysroot installed from the script. Branch oe/dizzy, commit 200f6cafc878d4c26871fc56d21ecc8eaa9aa61b.
The libjpeg-turbo recipe is in meta-oe, and I'm afraid the Yocto Project doesn't generally maintain recipes in that layer, but please report this issue to the openembedded-devel@lists.openembedded.org mailing list so that someone there can look into it.
The link http://www.openembedded.org/wiki/Bug_tracking says oe bugs should be reported here as well, can you please confirm and reopen the bug? Btw I tried to send it to that mailing list, but it is members-only.
It is specific and says "Bugs in OpenEmbedded-Core layer", and libjpeg-turbo isn't in OE-Core, at least at the moment (though it might be worth considering at some point if libjpeg should be replaced with it). Unfortunately the OE mailing lists have to be members-only due to previous unpleasant experiences with spammers, so you do need to subscribe before sending - but you can subscribe and then turn off mail delivery in the list options if you'd rather not receive postings.