Bugzilla Bug 126432

When I try to delete a user from my system, I always get this error message
since the last upgrade of shadow (sys-apps/shadow-4.0.14-r1)!

With sys-apps/shadow-4.0.14-r1:
MindLess ~ # useradd bob
MindLess ~ # LC_ALL="en_US" userdel bob
userdel: error removing group entry
userdel: error removing shadow group entry
MindLess ~ #


With sys-apps/shadow-4.0.7-r4:
MindLess ~ # useradd bob
MindLess ~ # LC_ALL="en_US" userdel bob
MindLess ~ #


Portage 2.0.54 (default-linux/x86/2006.0, gcc-3.4.5, glibc-2.3.5-r2,
2.6.15-gentoo-r4 i686)
=================================================================
System uname: 2.6.15-gentoo-r4 i686 Intel(R) Pentium(R) M processor 1.80GHz
Gentoo Base System version 1.6.14
dev-lang/python:     2.4.2
sys-apps/sandbox:    1.2.12
sys-devel/autoconf:  2.13, 2.59-r7
sys-devel/automake:  1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r1
sys-devel/binutils:  2.16.1
sys-devel/libtool:   1.5.22
virtual/os-headers:  2.6.11-r2
ACCEPT_KEYWORDS="x86"
AUTOCLEAN="yes"
CBUILD="i686-pc-linux-gnu"
CFLAGS="-O3 -march=pentium-m -fomit-frame-pointer -fforce-addr -mmmx -msse
-msse2 -mfpmath=sse -pipe"
CHOST="i686-pc-linux-gnu"
CONFIG_PROTECT="/etc /usr/kde/2/share/config /usr/kde/3.4/env
/usr/kde/3.4/share/config /usr/kde/3.4/shutdown /usr/kde/3/share/config
/usr/lib/X11/xkb /usr/share/config /var/bind /var/qmail/control"
CONFIG_PROTECT_MASK="/etc/gconf /etc/splash /etc/terminfo /etc/env.d"
CXXFLAGS="-O3 -march=pentium-m -fomit-frame-pointer -fforce-addr -mmmx -msse
-msse2 -mfpmath=sse -pipe"
DISTDIR="/usr/portage/distfiles"
FEATURES="autoconfig distlocks sandbox sfperms strict"
GENTOO_MIRRORS="http://distfiles.gentoo.org
http://distro.ibiblio.org/pub/linux/distributions/gentoo"
LANG="fr_CA"
LC_ALL="fr_CA"
LINGUAS="fr"
PKGDIR="/usr/portage/packages"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/usr/portage"
SYNC="rsync://rsync.gentoo.org/gentoo-portage"
USE="x86 X acl acpi alsa apache2 arts audiofile avi bash-completion berkdb
bitmap-fonts bzip2 cdr cli crypt ctype cups curl dba dbus directfb dri dvd dvdr
dvdread eds emboss encode esd ethereal exif expat fam fastbuild ffmpeg firefox
flac foomaticdb force-cgi-redirect fortran ftp gd gdbm gif glut gmp gnome gpm
gstreamer gtk2 hal iconv idn imlib innodb ipv6 jabber java jpeg lcms libg++
libwww lirc mad memlimit mhash mikmod mmx mng motif mp3 mpeg mysql ncurses nls
nptl nptlonly ntpl ogg oggvorbis openal opengl oss pam pcmcia pcre pdflib perl
php png posix postgres python qt quicktime readline samba sdl session simplexml
soap sockets speex spl sqlite sse sse2 ssl svga tcltk tcpd threads tiff
tokenizer truetype truetype-fonts type1-fonts udev unicode usb vorbis wifi
xinerama xml xml2 xmms xsl xv xvid zlib linguas_fr userland_GNU kernel_linux
elibc_glibc"
Unset:  ASFLAGS, CTARGET, LDFLAGS, MAKEOPTS, PORTDIR_OVERLAY

Upgrading to sys-apps/shadow-4.0.14-r2 did not solve the problem.

*** Bug 126431 has been marked as a duplicate of this bug. ***

Setting USERGROUPS_ENAB to "no" in /etc/login.defs seems to solve the problem!
But why?

bug introduced in shadow 4.0.14 and already fixed upstream

grabbed upstream fix and added shadow-4.0.14-r3