[PATCH v15 11/12] package_rpm.bbclass: Suppress pkgconfig() Requires for sstate compatibility

[Sumanth Gavini <sumanth.gavini@windriver.com>]

rpm 4 had two dependency generation systems: an external generator
(System 1) and an internal fileattr-based generator (System 2).
OE used System 1 and disabled everything via:

  --define '_use_internal_dependency_generator 0'
  --define '__find_requires %{nil}'
  --define '__find_provides %{nil}'

This meant pkgconfigdeps.sh (part of System 2) never ran in OE builds.

rpm 6 removed System 1 entirely. For v6-format packages it only runs
the fileattr system (System 2), and _use_internal_dependency_generator
is ignored.  So __find_requires %{nil} no longer works, and
pkgconfigdeps.sh now runs for the first time in OE builds.

pkgconfigdeps.sh --requires generates both "Requires:/usr/bin/pkg-config"
and "Requires: pkgconfig(foo)" for each .pc dependency.  This creates a
sstate compatibility problem: packages built before the pkgconfigdeps.sh
fix (which unsets PKG_CONFIG_SYSROOT_DIR) have no "Provides:pkgconfig(foo)"
because pkg-config was failing silently.  When DNF installs a mix of old
sstate packages (no Provides) and new packages (now generating
Requires),
it fails with:

  nothing provides pkgconfig(zlib) needed by elfutils-dev
  nothing provides pkgconfig(x11) needed by libdrm-dev

In rpm 6, the correct way to suppress a specific fileattr generator is
via its per-generator macro.  Set __pkgconfig_requires %{nil} so new
packages don't generate Requires that old sstate packages can't satisfy.
Provides generation (__pkgconfig_provides) is kept so packages still
advertise their pkgconfig modules.

OE manages build and runtime deps via DEPENDS/RDEPENDS; auto-generated
pkgconfig() Requires from rpmbuild are not needed.  This follows the
same pattern as the existing __font_provides %{nil}.

Signed-off-by: Sumanth Gavini <sumanth.gavini@windriver.com>
---
 meta/classes-global/package_rpm.bbclass | 1 +
 1 file changed, 1 insertion(+)

diff --git a/meta/classes-global/package_rpm.bbclass b/meta/classes-global/package_rpm.bbclass
index 51ad195baa..1e016971f5 100644
--- a/meta/classes-global/package_rpm.bbclass
+++ b/meta/classes-global/package_rpm.bbclass
@@ -599,6 +599,7 @@ python do_package_rpm () {
     cmd = cmd + " --define 'use_source_date_epoch_as_buildtime 1'"
     cmd = cmd + " --define '_buildhost reproducible'"
     cmd = cmd + " --define '__font_provides %{nil}'"
+    cmd = cmd + " --define '__pkgconfig_requires %{nil}'"
     cmd = cmd + " --define '_unpackaged_files_terminate_build 0'"
     cmd = cmd + " --define 'debug_package %{nil}'"
     cmd = cmd + " --define '_tmppath " + workdir + "'"