[OE-core] opkg intercept for ldconfig on oe-core

[Ben Shelton]

Hi all,

I was looking at the opkg intercept functionality, and if I'm understanding this
properly, it looks like it changes the PATH so that e.g. ldconfig is redirected
to the script under /usr/share/opkg/intercept/ldconfig when running postinst
scripts.  That way, when installing a bunch of libraries, ldconfig can be run
once at the end rather than once for every package.

However, the postinst scripts for libraries are generated with
ldconfig_postinst_fragment() in meta/classes/package.bbclass, which looks like
this:

ldconfig_postinst_fragment() {
if [ x"$D" = "x" ]; then
	if [ -x /sbin/ldconfig ]; then /sbin/ldconfig ; fi
fi
}

Because this script uses the full absolute path to ldconfig, the opkg intercept
ldconfig script isn't being invoked.  I verified this by putting an echo in
/usr/share/opkg/intercept/ldconfig, which I saw only when I changed my package's
postinst script to

ldconfig_postinst_fragment() {
if [ x"$D" = "x" ]; then
	ldconfig
fi
}

In the history of package.bbclass, it originally used to look like this, but was
changed in 2008 in a sync from OE.dev.

Is this expected behavior?  Is opkg intercept still supported?  Should we fix
this, and if so, what would be a safe way to do it?

Thanks,
Ben