Unable to install breqn and cadabra on Arch Linux

Question

Hi,
I am running Arch Linux (64-bit) on my Dell XPS 15 laptop. I use LaTeX for all my scientific typesetting. When I was running Fedora on this system earlier, I used Cadabra, an open source symbolic manipulation program suited to calculations in quantum field theory. I tried to install cadabra in Arch using yaourt, but I get the following error message:
[root@krypton ~]# yaourt cadabra
1 aur/cadabra 1.29-1 (2)
Cadabra is a computer algebra system (CAS)
2 aur/modglue 1.16-2 (1)
Modglue library for Cadabra computer algebra system (CAS)
==> Enter n° of packages to be installed (ex: 1 2 3 or 1-3)
==> -------------------------------------------------------
==> 1
==> Downloading cadabra PKGBUILD from AUR...
x PKGBUILD
x cadabra.install
First Submitted: Wed, 16 Sep 2009 08:01:06 +0000
cadabra 1.29-1
( Unsupported package: Potentially dangerous ! )
==> Edit PKGBUILD ? [Y/n] ("A" to abort)
==> ------------------------------------
==> n
==> cadabra dependencies:
- conlie (building from AUR)
- modglue>=1.16 (building from AUR)
- breqn (building from AUR)
==> Edit cadabra.install ? [Y/n] ("A" to abort)
==> -------------------------------------------
==> n
==> Continue building cadabra ? [Y/n]
==> ---------------------------------
==>
==> Building and installing package
==> Install or build missing dependencies for cadabra:
==> Downloading breqn PKGBUILD from AUR...
x breqn.install
x PKGBUILD
First Submitted: Wed, 16 Sep 2009 08:00:09 +0000
breqn 1.2b-2
( Unsupported package: Potentially dangerous ! )
==> Edit PKGBUILD ? [Y/n] ("A" to abort)
==> ------------------------------------
==> n
==> breqn dependencies:
- texlive-bin (already installed)
- texlive-core (already installed)
==> Edit breqn.install ? [Y/n] ("A" to abort)
==> -----------------------------------------
==> n
==> Continue building breqn ? [Y/n]
==> -------------------------------
==>
==> Building and installing package
==> WARNING: Building package as root is dangerous.
Please run yaourt as a non-privileged user.
==> Making package: breqn 1.2b-2 (Thu May 31 20:10:59 IST 2012)
==> Checking runtime dependencies...
==> Checking buildtime dependencies...
==> Retrieving Sources...
-> Downloading mh.zip...
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 2196k 100 2196k 0 0 74677 0 0:00:30 0:00:30 --:--:-- 73748
==> Validating source files with md5sums...
mh.zip ... FAILED
==> ERROR: One or more files did not pass the validity check!
==> ERROR: Makepkg was unable to build breqn.
==> Restart building breqn ? [y/N]
==> ------------------------------
==>
Surprisingly, a search on google did not reveal anything useful. Apparently the problem is validating the package 'breqn' which is a prerequisite for cadabra, but fails to install through yaourt because of some md5 checksum validation error (as I understand). And it seems there is no override for this in yaourt.
Any suggestions to help me get cadabra to work will be greatly appreciated.
Thanks in advance!
References:
1. http://aur.archlinux.org/packages.php?ID=30207
2. http://cadabra.phi-sci.com/
Last edited by darkmav (2012-05-31 14:41:57)

Answer 1

Your problem is that the file the PKGBUILD is downloading is not the same one that the creator of the PKGBUILD was working with.
an md5sum is a hash (a fingerprint, if you will) of the file.  When the PKGBUILD was created, that fingerprint was included in the file.  That yours does not match means one of two things:
1. The file you downloaded was either corrupt, or has been tampered with, or
2. The file you downloaded has been updated by the author, but the PKGBUILD has not been updated.
If it is case 1, stop.  If it is case 2, you can do the following:
The Cadabra PKGBUILD was updated last June (almost a year ago).  You can either post a comment to the AUR and see if the maintainer will fix it, or you can fix the PKGBUILD yourself and (hopefully) post the changes back to the AUR as a comment.
# Contributor: Dariusz 'quasi' Panchyrz <[email protected]>
pkgname=cadabra
pkgver=1.29
pkgrel=1
pkgdesc="Cadabra is a computer algebra system (CAS)"
arch=('i686' 'x86_64')
url="http://cadabra.phi-sci.com/"
license=('GPL')
depends=('conlie' 'modglue>=1.16' 'breqn')
install=$pkgname.install
source=(http://cadabra.phi-sci.com/$pkgname-$pkgver.tar.gz)
md5sums=('ea6e64535e6a9abe8810e5baa6a579a8')
build() {
cd $startdir/src/$pkgname-$pkgver/
./configure --prefix=$startdir/pkg/usr/
make || return 1
make install || return 1
Notice the md5sums entry in the PKGBUILD above.  It needs to be updated in accordance with this article and then built on your machine using makepkg.  I strongly suggest you not user a helper for this, but rather use the methods described here
Last edited by ewaller (2012-05-31 15:09:09)