ASSUME_PROVIDED and pkg-config-native

[Ola x Nilsson <ola.x.nilsson@axis.com>]

Hi,

It seems it's not possible to use pkg-config to find .pc files of
all native recipes that are in the ASSUME_PROVIDED list.  Is this
supposed to work and I'm doing something wrong?  I'd appreciate any
pointers. 

Some background: 

I ran into a problem with a recipe using the Meson that had

DEPENDS = "libxcrypt apr-util"
BBCLASSEXTEND = "native"

In the native case, libaprutil.so is linked against host
libcrypt.so.1, but this recipe tries to link against libxcrypt.so.2
from libxcrypt-native, causing a conflict.

apr-util does not DEPENDS on virtual/crypt; for target builds,  it's
pulled in via util-linux. Maybe virtual/crypt should be added to
PACKAGECONFIG[crypto], but that's not really the core issue here.

virtual/crypt-native is in ASSUME_PROVIDED.  When switching to DEPENDS =
"virtual/crypt" Meson's dependency('libxcrypt') can no longer find the
.pc file, neither in recipe-sysroot-native nor in
/usr/lib/x86_64-linux-gnu/pkgconfig.  The pkg-config-native and
pkg-config wrappers around pkgconf ensure that system library folders
are not searched.

I don't think EXTRA_NATIVE_PKGCONFIG_PATH can be used here.  We want the
system folders to be searched last, and ideally only for packages listed
in ASSUME_PROVIDED.  In my case the project depends on several libraries
whose options are found using pkg-config.  I don't want to accidentaly
find a system library for something that is not ASSUME_PROVIDED. 

-- 
Ola Nilsson