[yocto] cannot add nativesdk package to toolchain

[Guillaume Sanahuja]

Hello,

I am trying to add a nativesdk dev package (from a custom recipe) to a 
toolchain, in poky 10.0.0. I have added nativesdk-mypackage-dev to 
TOOLCHAIN_HOST_TASK variable, but when I bitbake it I got the following 
error:
  Collected errors:
|  * opkg_install_cmd: Cannot install package nativesdk-mypackage-dev.
The log does not say anything else...

Yet, mypackage.bb contains BBCLASSEXTEND = "nativesdk" and I can see the 
ipks in the directory 
tmp/work/x86_64-nativesdk-pokysdk-linux/nativesdk-mypackage

Now, I am trying to do the same thing with non custom packages, and I 
see a strange behaviour:
-adding nativesdk-libmpc-dev to TOOLCHAIN_HOST_TASK works
-addinc nativesdk-lzo-dev to TOOLCHAIN_HOST_TASK fails with same error:
Collected errors:
|  * opkg_install_cmd: Cannot install package nativesdk-lzo-dev.

If I look at the 2 recipes, they are very close; so I do not understand 
why the second one fails. Again, all ipks exist in 
tmp/work/x86_64-nativesdk-pokysdk-linux/ directory.

What am I doing wrong? Or how do I install a dev package for the host in 
the toolchain?
Thanks for your help.
Regards,
Guillaume