[pacman-dev] Inconsistency of makepkg's activities in devel_check()

[Benjamin Richter]

Hello developers. :-)

I noticed that makepkg handles Mercurial repositories differently from
CVS/SVN/Bazaar/etc. With the others, $newpkgver is either computed using
$(date ...) or retrieved from the online repository and the PKGBUILD is
responsible for retrieving the contents as it is demonstrated here:
http://wiki.archlinux.org/index.php/Arch_CVS_%6_SVN_PKGBUILD_guidelines.

Only with hg the repository is automatically cloned, pulled and updated:

- - - - - makepkg, in devel_check(), lines 1211 and following - - - - - 
if [ -n "${_darcstrunk}" -a -n "${_darcsmod}" ] ; then
    [ $(type -p darcs) ] || return 0
    msg "$(gettext "Determining latest darcs revision...")"
    newpkgver=$(date +%Y%m%d)
elif [ -n "${_cvsroot}" -a -n "${_cvsmod}" ] ; then
    [ $(type -p cvs) ] || return 0
    msg "$(gettext "Determining latest cvs revision...")"
    newpkgver=$(date +%Y%m%d)
elif [ -n "${_gitroot}" -a -n "${_gitname}" ] ; then
    [ $(type -p git) ] || return 0
    msg "$(gettext "Determining latest git revision...")"
    newpkgver=$(date +%Y%m%d)
elif [ -n "${_svntrunk}" -a -n "${_svnmod}" ] ; then
    [ $(type -p svn) ] || return 0
    msg "$(gettext "Determining latest svn revision...")"
    newpkgver=$(LC_ALL=C svn info $_svntrunk | sed -n 's/^Last Changed Rev: \([0-9]*\)$/\1/p')
elif [ -n "${_bzrtrunk}" -a -n "${_bzrmod}" ] ; then
    [ $(type -p bzr) ] || return 0
    msg "$(gettext "Determining latest bzr revision...")"
    newpkgver=$(bzr revno ${_bzrtrunk})
elif [ -n "${_hgroot}" -a -n "${_hgrepo}" ] ; then
    [ $(type -p hg) ] || return 0
    msg "$(gettext "Determining latest hg revision...")"
    if [ -d ./src/$_hgrepo ] ; then
        cd ./src/$_hgrepo
        hg pull
        hg update
    else
        [[ ! -d ./src/ ]] && mkdir ./src/
        hg clone $_hgroot/$_hgrepo ./src/$_hgrepo
        cd ./src/$_hgrepo
    fi
    newpkgver=$(hg tip --template "{rev}")
    cd ../../
fi
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

This behaviour seems to be widely unknown, which leads to a lot of
PKGBUILDS pulling/updating twice - first automatically and then again in
build(): 
http://aur.archlinux.org/packages/aldrin-hg/aldrin-hg/PKGBUILD
http://aur.archlinux.org/packages/audacious-hg/audacious-hg/PKGBUILD
...

I just wonder why hg is handled differently and whether it wouldn't be
better

   a) also to clone/update/pull/... svn/bzr/cvs/etc. in devel_check() -
cf. http://wiki.archlinux.org/index.php/The_Arch_Way regarding
automation 

or b) to remove devel_check() entirely, but leave devel_update() and let
the PKGBUILD handle such changes, eg. like this:

- - - complete example PKGBUILD in case anyone wants to try it - - - 
# Contributor: Artyom Smirnov <smirnoffjr at gmail.com>
# Contributor: Benjamin Richter <webmaster at waldteufel-online.net>

pkgname=gajim-hg
pkgver=10960
pkgrel=1
pkgdesc="Jabber/XMMP instant messenger client written in PyGTK"
arch=('i686' 'x86_64')
url="http://gajim.org"
license=('GPL')
depends=('python>=2.5' 'pygtk>=2.12' 'sqlite3' 'dnsutils')
makedepends=('python>=2.5' 'pygtk>=2.12' 'gtk2' 'libxss' 'dbus'
             'gtkspell' 'intltool>=0.40.1' 'automake>=1.8'
             'autoconf>=2.59' 'libtool' 'pkgconfig>=0.19')
optdepends=('pyopenssl: secure SSL/TLS'
            'pycrypto: End to end encryption'
            'dbus-glib: link-local messaging (install python-avahi!)'
            'python-avahi: link-local messaging (install dbus-glib!)'
            'dnsutils: SRV support'
            'gtkspell: Spell checking (install aspell-LANG!)'
            'gnome-python-extras: GNOME integration'
            'gnome-python-desktop: Keyring support'
            'python-notify: Notification popups'
            'dbus-python'
            'python-sexy: for clickable URLs'
            'python-kerberos>=1.1: GSSAPI authentication')
provides=('gajim')
conflicts=('gajim' 'gajim-svn')
options=(!libtool)
source=()
md5sums=()

scm_hg() {
    [[ -d "$2" ]] || hg clone "$1" "$2" || return

    cd "$2" ; hg pull -u || return
    newpkgver=$(hg tip --template '{rev}')
}

scm_retrieve() {
   [[ -z "$REPO_LATEST" ]] || return 0
   export REPO_LATEST=1

   msg "$(gettext "Determining latest $1 revision...")"

   cd "${srcdir}"
   "scm_${1}" "$2" "$3"
   msg2 "$(gettext 'Version found: %s')" "${newpkgver}"

   cd "${startdir}"
   devel_update
}

scm_retrieve hg http://hg.gajim.org/gajim gajim

build() {
   cp -al gajim gajim-build
   cd gajim-build

   ./autogen.sh || return
   ./configure --prefix=/usr || return
   make || return
   make DESTDIR="${pkgdir}" install || return

   cd ..
   rm -r gajim-build

   find "${pkgdir}/usr/share/gajim/" -name "*.pyo" | xargs rm
}
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
cf. http://wiki.archlinux.org/index.php/The_Arch_Way regarding freedom
(in this case: ... of the PKGBUILDer to choose by which means to
retrieve sources under SCM)

btw.: This latter approach already works without any change in makepkg.
The question is whether it is advisable, especially because there is
code outside build() which is run when the PKGBUILD is sourced, which
happens twice because of fakeroot. This is why this PKGBUILD needs
either the variable $REPO_LATEST or a rather ugly check whether makepkg
is running in fakeroot (INFAKEROOT=1), which I'd rather not use because
$INFAKEROOT is more like an implementation detail of makepkg. 

All this could be avoided by introducing another function - eg. update()
- into the PKGBUILD which is run only once - that is: after sourcing the
PKGBUILD when outside fakeroot - and sets $newpkgver, which would then
be read by devel_update, which would be called after update()
automatically. 

Makepkg would detect the existence of a function called update() and
display the appropriate messages - eg. "Updating PKGBUILD...". 

The PKGBUILD would then look like this - provided that update() is
called in $srcdir:

- - - - - - - - - - - - - - another example - - - - - - - - - - - - - - 
pkgname=gajim-hg
#... variables as before

update() {
   [[ -d gajim ]] || hg clone http://hg.gajim.org/gajim || return 1
   hg pull -u -R gajim || return 1
   newpkgver=$(hg tip --template '{rev}' -R gajim)
}

#... build() as before
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

update() could also be called scm_retrieve() or something like that.

Any opinions?

Kind regards.
Benjamin Richter (aka Waldteufel)