[PATCH v2] dpkg: Account for empty local apt cache after package build

[Jan Kiszka <jan.kiszka@siemens.com>]

From: Jan Kiszka <jan.kiszka@siemens.com>

A build dependency-free package combined with sstate caching and cleared
deb cache can trigger

| cp -Ln --no-preserve=owner /var/cache/apt/archives/*.deb -t /home/builder/example-raw/rootfs/var/cache/apt/archives/
| --------------------------------------------------------------------------------------------------------------------
|
| cp: cannot stat '/var/cache/apt/archives/*.deb': No such file or directory
|
| E: Command 'cp -Ln --no-preserve=owner /var/cache/apt/archives/*.deb -t /home/builder/example-raw/rootfs/var/cache/apt/archives/' failed to run.

Account for that.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---

Changes in v2:
 - avoid returning error via negativ [ -n ] result

 meta/classes/dpkg.bbclass | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/meta/classes/dpkg.bbclass b/meta/classes/dpkg.bbclass
index d89b0fd9..d61e9377 100644
--- a/meta/classes/dpkg.bbclass
+++ b/meta/classes/dpkg.bbclass
@@ -109,7 +109,7 @@ dpkg_runbuild() {
         --chroot-setup-commands="mkdir -p ${deb_dir}" \
         --chroot-setup-commands="ln -sf ${ext_deb_dir}/*.deb -t ${deb_dir}/" \
         --finished-build-commands="rm -f ${deb_dir}/sbuild-build-depends-main-dummy_*.deb" \
-        --finished-build-commands="cp -Ln --no-preserve=owner ${deb_dir}/*.deb -t ${ext_deb_dir}/" \
+        --finished-build-commands="[ -z "$(find ${deb_dir} -maxdepth 1 -name '*.deb' -print -quit)" ] || cp -Ln --no-preserve=owner ${deb_dir}/*.deb -t ${ext_deb_dir}/" \
         --finished-build-commands="cp /var/log/dpkg.log ${ext_root}/dpkg_partial.log" \
         --debbuildopts="--source-option=-I" \
         --build-dir=${WORKDIR} --dist="isar" ${DSC_FILE}
-- 
2.35.3