How to add do_populate_sdk task to avro-c BitBake recipe? - sdk

Question

This question is specific to avro-c, but the solution may be generalized to other packages in the OpenEmbedded BitBake system.
How do I create a do_populate_sdk task for avro-c?
I want to generate a Yocto SDK which includes avro-c. The avro-c layer in meta-openembedded is very small:
avro
├── avro-c
│   └── 0001-avro-c-Fix-build-with-clang-compiler.patch
└── avro-c_1.8.1.bb
The avro-c_1.8.1.bb recipe is only 20 lines:
SUMMARY = "Apache Avro data serialization system."
HOMEPAGE = "http://apr.apache.org/"
SECTION = "libs"
LICENSE = "Apache-2.0"
LIC_FILES_CHKSUM = "file://LICENSE;md5=73bdf70f268f0b3b9c5a83dd7a6f3324"
DEPENDS = "jansson zlib xz"
PV .= "+git${SRCPV}"
SRCREV = "4b3677c32b879e0e7f717eb95f9135ac654da760"
SRC_URI = "git://github.com/apache/avro \
file://0001-avro-c-Fix-build-with-clang-compiler.patch;patchdir=../../ \
"
S = "${WORKDIR}/git/lang/c"
LDFLAGS_append_libc-uclibc = " -lm"
inherit cmake
A target image which includes avro-c builds successfully, and ls /usr/bin/avro* lists the Avro functions.
However, avro-c is not included in the host SDK build. One way to troubleshoot this is to try the two commands:
$ bitbake avro-c
$ bitbake avro-c -c populate_sdk
The first command completes successfully. The second command fails with the following error messages:
ERROR: Task do_populate_sdk does not exist for target avro-c (/home/rdepew/workspace/clean1/build/../layers/meta-sporian/recipes-support/avro/avro-c_1.8.1.bb:do_populate_sdk). Close matches:
do_populate_lic
do_populate_sysroot
ERROR: Command execution failed: 1
I looked for clues in the other layers in my build system. It appeared that creating the file avro-c_%.bbappend, containing the single line
inherit nativesdk
might do the trick, but that generated two more BitBake error messages:
ERROR: Nothing PROVIDES 'virtual/x86_64-pokysdk-linux-compilerlibs' (but /home/rdepew/workspace/clean1/build/../layers/meta-sporian/recipes-support/avro/avro-c_1.8.1.bb DEPENDS on or otherwise requires it). Close matches:
virtual/nativesdk-x86_64-pokysdk-linux-compilerlibs
virtual/x86_64-pokysdk-linux-go-crosssdk
virtual/x86_64-pokysdk-linux-gcc-crosssdk
ERROR: Required build target 'avro-c' has no buildable providers.
Missing or unbuildable dependency chain was: ['avro-c', 'virtual/x86_64-pokysdk-linux-compilerlibs']
... and that's where I'm stuck. I'm not sure where to go from here.
Online places that I have researched:
I don't know if it's appropriate to list the URLS of places where I have looked for the answer. They include the GitHub repository for Avro, the Yocto Project ADT manual, and four related questions on StackOverflow. If it's appropriate, I will edit this question to include the URLs.

Answer 1

The right way to add something to SDK (or eSDK - Extended SDK) is via the image of your choice. So, the steps are:
Add a package to the image:
IMAGE_INSTALL_append = " avro-c"
Create Yocto SDK for an image of your choice:
bitbake core-image-full-cmdline -c populate_sdk
Create Yocto eSDK for an image of your choice:
bitbake core-image-full-cmdline -c populate_sdk_ext
Have fun! :-)

Answer 2

You need the following line in your recipe
BBCLASSEXTEND = "nativesdk"
This extends the same recipe to build for sdk as well. See here for more details.
EDIT:
do_populate_sdk: This task applies only for the image recipe. This handles two operations.
Target part: Compiles and installs the header and libraries for the target platform.
Host part: Installs the host part of the library and header based on SDKMACHINE
During these operations, it finds the list of packages needed for the SDK by examining the BBCLASSEXTEND variable and builds the nativesdk-<recipe_name> for combines them together in SDK.
So you have do_populate_sdk for image recipe which bundles the packages together.
See yocto manual here for more details.