[yocto] building python3-posix-ipc on pyro

[Bill Randle]

I successfully built python3-posix-ipc_1.0.0 on morty several times
without error. When I tried to build it on pyro, using the exact same
bb file and source I get warnings which lead to incorrect behavior.
(Cross-compile for ARM.)

I know this recipe is not part of OE-Core, but I'm wondering if anyone
has tried to build it anyway or seen a similar problem.

This is my .bb file (loosely based on the recipe in meta-openstack,
which is for python2):

DESCRIPTION = "POSIX IPC primitives (semaphores, shared memory and
message queues) for Python"
HOMEPAGE = "http://semanchuk.com/philip/posix_ipc/"
SECTION = "devel/python"
LICENSE = "BSD"
LIC_FILES_CHKSUM = "file://LICENSE;md5=d92bb5439aee694c0a87bfb51579e37b"

PR = "r0"

PYPI_PACKAGE = "posix_ipc"

SRC_URI[md5sum] = "85607a392087715ac3a3c7ded2492d06"
SRC_URI[sha256sum] =
"9c93070374ca672725575e5c9874930c8cde69367fb90378b2255e048e31efcb"

inherit pypi setuptools3

# RDEPENDS_default:
RDEPENDS_${PN} += " \
        "
    ----------

The head of the log.compile file on morty is:

DEBUG: Executing shell function do_compile
running build
running build_ext
building 'posix_ipc' extension
creating build
creating build/temp.linux-x86_64-3.5
    ----------
While the head of log.do_compile on pyro looks like this:

DEBUG: Executing shell function do_compile
******************************************************************************
* Setup can't determine if it needs to link to the realtime libraries on your
* system, so it will default to 'no' which may not be correct.
*
* Please report this message and your operating system info to the package
* maintainer listed in the README file.
******************************************************************************
******************************************************************************
* Setup can't determine the value of PAGE_SIZE on your system, so it will
* default to 4096 which may not be correct.
*
* Please report this message and your operating system info to the package
* maintainer listed in the README file.
******************************************************************************
running build
running build_ext
building 'posix_ipc' extension
creating build
creating build/temp.linux-x86_64-3.5
    ----------

Now the output on pyro totally makes sense when I look at setup.py
(which uses probe.py) because the probe function is trying to compile
a test file to see if librt is required or not. It's not surprising it
fails, since I'm building for ARM.

I can go in and patch the probe function so it returns Yes to indicate
librt is required, but my question why no error when building for
morty and what might have changed? As I said, the .bb file and the
source package are identical in both cases.

    -Bill