[debhelper-devel] Bug#797742: debhelper: dh_fixperms and dh_md5sums might run into "/usr/bin/xargs: ... Argument list too long"

[Tobias Grimm]

Package: debhelper
Version: 9.20150101
Severity: normal

I'm building packages using cowbuilder/pbuilder. Recently I also do this for
armhf using qemu. There it happens, that I run into problems with dh_fixperms
and dh_md5sums for packages with lots of files.
e.g. one package contains about 1459 files, wich makes an argument list of
about 140kB. `xargs --show-limits` reports:

Your environment variables take up 6150 bytes
POSIX upper limit on argument length (this system): 2088954
POSIX smallest allowable upper limit on argument length (all systems): 4096
Maximum length of command we could actually use: 2082804
Size of command buffer we are actually using: 131072

....and dh_md5sums causes a "/usr/bin/xargs: md5sum: Argument list too long"

To be honest, I couldn't figure out, why this only happens for my armhf builds
and not for i386 and amd64. `xargs --show-limits` reports always the same
values.

But I think at least the xarg-calls for md5sum and chown should be replaced
with something safer like "xargs -r0 -L10 md5sum" to avoid trouble with
packages containing a lot of files.



-- System Information:
Debian Release: 8.0
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.16.0-4-amd64 (SMP w/8 CPU cores)
Locale: LANG=de_DE.utf8, LC_CTYPE=de_DE.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages debhelper depends on:
ii  binutils      2.25-5
ii  dpkg          1.17.25
ii  dpkg-dev      1.17.25
ii  file          1:5.22+15-2
ii  libdpkg-perl  1.17.25
ii  man-db        2.7.0.2-5
ii  perl          5.20.2-3
ii  po-debconf    1.0.16+nmu3

debhelper recommends no packages.

Versions of packages debhelper suggests:
ii  dh-make  1.20140617

-- no debconf information