Do not fail source retrieval step with apt >=1.1

apt >=1.1 tries to drop privileges which fails in our typical setup with:

| W: Can't drop privileges for downloading as file 'zsh_5.2-2.dsc' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied)

Instead let's check for actual errors (starting with "E:"),
and do not fail the build if there warnings only ("W:").

diff --git a/etc/grml/fai/config/scripts/GRMLBASE/03-get-sources b/etc/grml/fai/config/scripts/GRMLBASE/03-get-sources
index 4e20182..4deb887 100755 (executable)
--- a/etc/grml/fai/config/scripts/GRMLBASE/03-get-sources
+++ b/etc/grml/fai/config/scripts/GRMLBASE/03-get-sources
@@ -42,11 +42,19 @@ apt-get --download-only source "$package" 2>>/grml-live/sources/errors.log
 EOT
   done
 
-  if grep -q . "${target}/grml-live/sources/errors.log" ; then
+  if grep -q '^E:' "${target}/grml-live/sources/errors.log" ; then
     echo "Errors noticed while retrieving sources:" >&2
     cat "${target}/grml-live/sources/errors.log" >&2
     bailout
     exit 1
+  elif grep -q '^W:' "${target}/grml-live/sources/errors.log" ; then
+    echo "Warnings noticed while retrieving sources (not failing the build though):"
+    cat "${target}/grml-live/sources/errors.log"
+  elif grep -q '.' "${target}/grml-live/sources/errors.log" ; then
+    echo "Unclassified problems noticed while retrieving sources:" >&2
+    cat "${target}/grml-live/sources/errors.log" >&2
+    bailout
+    exit 1
   fi
 
 fi