[gentoo-user] Why is the introspection USE flag for glib being removed by emerge?

[Allan Gottlieb <gottlieb@nyu.edu>]

In package.use I have

    dev-libs/glib                    introspection

However emerge is removing it.

    emerge --ignore-default-opts -pv =dev-libs/glib-9999::gnome

    [ebuild   R   *] dev-libs/glib-9999  USE="static-libs -debug -doc -fam (-introspection) (-selinux) -test -xattr" 0 kB [1]

Can someone tell me why it is being removed and how to prevent the
removal?

thanks,
allan

PS This lack of introspection on glib is causing my update world to
fail.  I have the gnome overlay installed (for gnome3).

PPS The glib-9999 ebuild (from the gnome overlay) is

# Copyright 1999-2011 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Header: $

EAPI="3"
PYTHON_DEPEND="2"

inherit autotools gnome.org libtool eutils flag-o-matic pax-utils python virtualx
if [[ ${PV} = 9999 ]]; then
	inherit gnome2-live
fi

DESCRIPTION="The GLib library of C routines"
HOMEPAGE="http://www.gtk.org/"
SRC_URI="${SRC_URI}
	http://pkgconfig.freedesktop.org/releases/pkg-config-0.26.tar.gz" # pkg.m4 for eautoreconf

LICENSE="LGPL-2"
SLOT="2"
IUSE="debug doc fam +introspection selinux +static-libs test xattr"
if [[ ${PV} = 9999 ]]; then
	KEYWORDS=""
else
	KEYWORDS="~alpha ~amd64 ~arm ~hppa ~ia64 ~m68k ~mips ~ppc ~ppc64 ~s390 ~sh ~sparc ~x86 ~sparc-fbsd ~x86-fbsd"
fi

RDEPEND="virtual/libiconv
	sys-libs/zlib
	xattr? ( sys-apps/attr )
	fam? ( virtual/fam )"
DEPEND="${RDEPEND}
	>=sys-devel/gettext-0.11
	>=dev-util/gtk-doc-am-1.13
	doc? (
		>=dev-libs/libxslt-1.0
		>=dev-util/gtk-doc-1.13
		~app-text/docbook-xml-dtd-4.1.2 )
	test? ( dev-util/pkgconfig
		>=sys-apps/dbus-1.2.14 )"
PDEPEND="introspection? ( dev-libs/gobject-introspection )
	!<gnome-base/gvfs-1.6.4-r990" # Earlier versions do not work with glib

# XXX: Consider adding test? ( sys-devel/gdb ); assert-msg-test tries to use it

pkg_setup() {
	python_set_active_version 2
}

src_prepare() {
	[[ ${PV} = 9999 ]] && gnome2-live_src_prepare
	mv -vf "${WORKDIR}"/pkg-config-*/pkg.m4 "${WORKDIR}"/ || die

	if use ia64 ; then
		# Only apply for < 4.1
		local major=$(gcc-major-version)
		local minor=$(gcc-minor-version)
		if (( major < 4 || ( major == 4 && minor == 0 ) )); then
			epatch "${FILESDIR}/glib-2.10.3-ia64-atomic-ops.patch"
		fi
	fi

	# Don't fail gio tests when ran without userpriv, upstream bug 552912
	# This is only a temporary workaround, remove as soon as possible
	epatch "${FILESDIR}/${PN}-2.18.1-workaround-gio-test-failure-without-userpriv.patch"

	# Fix gmodule issues on fbsd; bug #184301
	epatch "${FILESDIR}"/${PN}-2.12.12-fbsd.patch

	# Fix test failure when upgrading from 2.22 to 2.24, upstream bug 621368
	epatch "${FILESDIR}/${PN}-2.24-assert-test-failure.patch"

	# Do not try to remove files on live filesystem, upstream bug #619274
	sed 's:^\(.*"/desktop-app-info/delete".*\):/*\1*/:' \
		-i "${S}"/gio/tests/desktop-app-info.c || die "sed failed"

	if ! use test; then
		# don't waste time building tests
		sed 's/^\(SUBDIRS =.*\)tests\(.*\)$/\1\2/' -i Makefile.am Makefile.in \
			|| die "sed failed"
	fi

	# Needed for the punt-python-check patch, disabling timeout test
	# Also needed to prevent croscompile failures, see bug #267603
	AT_M4DIR="${WORKDIR}" eautoreconf

	[[ ${CHOST} == *-freebsd* ]] && elibtoolize

	epunt_cxx
}

src_configure() {
	local myconf

	# Building with --disable-debug highly unrecommended.  It will build glib in
	# an unusable form as it disables some commonly used API.  Please do not
	# convert this to the use_enable form, as it results in a broken build.
	# -- compnerd (3/27/06)
	use debug && myconf="--enable-debug"

	# Always use internal libpcre, bug #254659
	econf ${myconf} \
		$(use_enable xattr) \
		$(use_enable doc man) \
		$(use_enable doc gtk-doc) \
		$(use_enable fam) \
		$(use_enable selinux) \
		$(use_enable static-libs static) \
		--enable-regex \
		--with-pcre=internal \
		--with-threads=posix \
		--disable-dtrace \
		--disable-systemtap
}

src_install() {
	local f
	emake DESTDIR="${D}" install || die "Installation failed"

	# Do not install charset.alias even if generated, leave it to libiconv
	rm -f "${ED}/usr/lib/charset.alias"

	# Don't install gdb python macros, bug 291328
	rm -rf "${ED}/usr/share/gdb/" "${ED}/usr/share/glib-2.0/gdb/"

	# This is there for git snapshots and the live ebuild, bug 351966
	emake README || die "emake README failed"
	dodoc AUTHORS ChangeLog* NEWS* README || die "dodoc failed"

	insinto /usr/share/bash-completion
	for f in gdbus gsettings; do
		newins "${ED}/etc/bash_completion.d/${f}-bash-completion.sh" ${f} || die
	done
	rm -rf "${ED}/etc"
}

src_test() {
	unset DBUS_SESSION_BUS_ADDRESS
	export XDG_CONFIG_DIRS=/etc/xdg
	export XDG_DATA_DIRS=/usr/local/share:/usr/share
	export G_DBUS_COOKIE_SHA1_KEYRING_DIR="${T}/temp"
	export XDG_DATA_HOME="${T}"
	unset GSETTINGS_BACKEND # bug 352451

	# Related test is a bit nitpicking
	mkdir "$G_DBUS_COOKIE_SHA1_KEYRING_DIR"
	chmod 0700 "$G_DBUS_COOKIE_SHA1_KEYRING_DIR"

	# Hardened: gdb needs this, bug #338891
	if host-is-pax ; then
		pax-mark -mr "${S}"/tests/.libs/assert-msg-test \
			|| die "Hardened adjustment failed"
	fi

	# Need X for dbus-launch session X11 initialization
	Xemake check || die "tests failed"
}

pkg_preinst() {
	# Only give the introspection message if:
	# * The user has it enabled
	# * Has glib already installed
	# * Previous version was different from new version
	if use introspection && has_version "${CATEGORY}/${PN}"; then
		if ! has_version "=${CATEGORY}/${PF}"; then
			ewarn "You must rebuild gobject-introspection so that the installed"
			ewarn "typelibs and girs are regenerated for the new APIs in glib"
		fi
	fi
}

pkg_postinst() {
	# Inform users about possible breakage when updating glib and not dbus-glib, bug #297483
	if has_version dev-libs/dbus-glib; then
		ewarn "If you experience a breakage after updating dev-libs/glib try"
		ewarn "rebuilding dev-libs/dbus-glib"
	fi
}