Build: Extract debian control files to sysroots

build/linux/sysroot_scripts/sysroot-creator.sh

Index: build/linux/sysroot_scripts/sysroot-creator.sh
diff --git a/build/linux/sysroot_scripts/sysroot-creator.sh b/build/linux/sysroot_scripts/sysroot-creator.sh
index 64d9ab44672abb0c08f79bd4968adc7a6a14132d..74f6bbb27f148ce3b7f77982bc41d73717199dad 100644
--- a/build/linux/sysroot_scripts/sysroot-creator.sh
+++ b/build/linux/sysroot_scripts/sysroot-creator.sh
@@ -375,7 +375,8 @@ InstallIntoSysroot() {
   Banner "Install Libs And Headers Into Jail"
 
   mkdir -p ${BUILD_DIR}/debian-packages
-  mkdir -p ${INSTALL_ROOT}
+  mkdir -p ${INSTALL_ROOT}/debian
+  touch ${INSTALL_ROOT}/debian/control

[Sam Clegg, 2016/10/11 03:06:46]

Why make an empty control file here?

[Tom (Use chromium acct), 2016/10/11 05:33:55]

you need it to run dpkg-shlibdeps

[Lei Zhang, 2016/10/12 01:15:47]

Maybe just add a brief comment to explain why it exists.

[Tom (Use chromium acct), 2016/10/12 01:23:48]

Done.

   while (( "$#" )); do
     local file="$1"
     local package="${BUILD_DIR}/debian-packages/${file##*/}"
@@ -397,9 +398,11 @@ InstallIntoSysroot() {
     echo "${sha256sum}  ${package}" | sha256sum --quiet -c
 
     SubBanner "Extracting to ${INSTALL_ROOT}"
-    dpkg --fsys-tarfile ${package}\
-      | tar -xf - -C ${INSTALL_ROOT}
+    dpkg-deb -x ${package} ${INSTALL_ROOT}
 
+    base_package=$(dpkg-deb --field ${package} Package)
+    mkdir -p ${INSTALL_ROOT}/debian/${base_package}/DEBIAN

[Sam Clegg, 2016/10/11 03:06:46]

How are these "/debian" directories then passed to dpkg-shlibdeps?

It seems a little strange to put all this stuff under /debian in the sysroot.

If it works I don't argue, but hopefully we can switch to more real sysroots
built with debbootstrap soon.

[Tom (Use chromium acct), 2016/10/11 05:33:55]

you cd to the dir containing debian/ and then run dpkg-shlibdeps
yeah it's not standard :(  but I needed some place to stuff the control files. 
It doesn't have to be at the root, but the directory needs to be named debian. 
Maybe /impl/debian would be better??

+    dpkg-deb -e ${package} ${INSTALL_ROOT}/debian/${base_package}/DEBIAN
   done
 
   # Prune /usr/share, leaving only pkgconfig