[PATCH] lxc: restore DEBUG_PREFIX_MAP in TARGET_LDFLAGS for LTO reproducibility

oe-core [1] removed DEBUG_PREFIX_MAP from TARGET_LDFLAGS to avoid passing
prefix-map options via the linker flags. This is fine for most projects
since DEBUG_PREFIX_MAP is also provided via CFLAGS at configure time.

However, lxc enables LTO by default, which causes link-time code generation
to (re)emit debug information during the link step. Without DEBUG_PREFIX_MAP
on the link command line, TMPDIR/WORKDIR paths can leak into DWARF,
triggering the buildpaths QA check and breaking reproducibility.

Append DEBUG_PREFIX_MAP back to TARGET_LDFLAGS for lxc to ensure prefix-map
options are visible during LTO link-time compilation.

[1]
https://git.openembedded.org/openembedded-core/commit/?id=1797741aad02b8bf429fac4b81e30cdda64b5448

Signed-off-by: Ricardo Salveti <[email protected]>
---
 recipes-containers/lxc/lxc_git.bb | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/recipes-containers/lxc/lxc_git.bb b/recipes-containers/lxc/lxc_git.bb
index 542134db..04db2ac0 100644
--- a/recipes-containers/lxc/lxc_git.bb
+++ b/recipes-containers/lxc/lxc_git.bb
@@ -63,6 +63,9 @@ EXTRA_OEMESON += "${PTEST_CONF} -Ddistrosysconfdir=${sysconfdir}/default"
 # No meson equivalent for these yet
 # EXTRA_OECONF += "--enable-log-src-basename --disable-werror"
 
+# LTO is enabled by default, expose prefix-map options to the linker for reproducibility
+TARGET_LDFLAGS:append = " ${DEBUG_PREFIX_MAP}"
+
 PACKAGECONFIG ??= "templates \
     ${@bb.utils.contains('DISTRO_FEATURES', 'systemd', 'systemd', '', d)} \
     ${@bb.utils.contains('DISTRO_FEATURES', 'selinux', 'selinux', '', d)} \
-- 
2.34.1