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On Alpine 2.4.3, tested busybox-1.19.4-r4 with alpine-conf-2.11.2-r0. Also tested busybox-1.20.1-r1.apk from edge repository.

With a large file list of >32768 bytes, I found that lbu would only commit the files in the list from approximately the first 32768 bytes.

Since http://git.alpinelinux.org/cgit/alpine-conf/commit/?id=4e857d18684667e7d9df3a0256e0b6e446284641, lbu provides the included file list via stdin to xargs, rather than a shell variable:

                        _gen_filelist_0 | xargs -0 $tar_create \
                                | gzip -c  >"$tmppkg"

which expands to:

apk audit --backup --quiet --recursive | tr '\n' '\0' |\
     xargs -0 tar -c --no-recursion | gzip -c >"$tmppkg"

Therefore this bug can now be triggered when using lbu include to store a large list of files.

To easily duplicate the fundamental problem in busybox xargs:

mkdir test
cd test
for a in `seq 1000 2000`; do
  echo 'hello' > aaaaabbbbbcccccdddddeeeeefffffggggghhhhh-$a
done
ls -1 | xargs tar -c --no-recursion | tar -t

At first I thought this commit might have been at fault http://git.busybox.net/busybox/commit/findutils/xargs.c?h=1\_19\_stable&id=4a96617095f40e3cfcf148a8a7d5d83f71079aa1, but I also tested Alpine 1.10 with busybox-1.16.2-r2 and duplicated the problem.

Running apk add findutils works around the problem on all systems tested.

(Running apk add tar or removing the —no-recursion option has no effect on this problem.)

(from redmine: issue id 1240, created on 2012-07-03, closed on 2012-07-08)

• Changesets:
  • Revision 15245c4a0eb62b0e1bcbac5063391e0d57a53799 by Natanael Copa on 2012-07-04T08:09:21Z:

lbu: do not use xargs

xargs will execute the command twice if the buffer becomes long enough.
This will break tar.

We also use -z instead of piping via gzip while here.

ref #1240

• Revision 1ab89daa by Natanael Copa on 2012-07-04T15:07:45Z:

main/alpine-conf: lbu: do not use xargs

ref #1240

• Revision b16dbb24 by Natanael Copa on 2012-07-04T15:09:30Z:

main/alpine-conf: lbu: do not use xargs

fixes #1240
(cherry picked from commit 1ab89daa7c0d4b46230a2608f04151214a266101)