Summary and Info:

Got negative Total Installed Size when I ran -Syu

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warning: config file /etc/pacman.conf, line 19: directive 'SyncFirst' in section 'options' not recognized.
:: Synchronizing package databases...
core is up to date
extra is up to date
community is up to date
multilib is up to date
phontech is up to date
:: Starting full system upgrade...
resolving dependencies...
warning: dependency cycle detected:
warning: lib32-gcc-libs will be installed before its gcc-libs-multilib dependency
looking for inter-conflicts...

Packages (136): akonadi-1.9.1-3 avogadro-1.1.0-4 binutils-multilib-2.23.2-1 boost-1.53.0-2 boost-libs-1.53.0-2 cfitsio-3.340-1 colord-0.1.31-1 cups-1.6.2-1
cups-filters-1.0.31-1 diffutils-3.3-1 dnssec-anchors-20130320-1 ffmpeg-1:1.2-2 file-5.14-1 firefox-20.0-1 gcc-libs-multilib-4.8.0-1
gcc-multilib-4.8.0-1 gdk-pixbuf2-2.26.5-2 gegl-0.2.0-6 glibc-2.17-4 gnokii-0.6.31-3 gnutls-3.1.10-1 gparted-0.15.0-1 graphviz-2.30.1-2
gst-plugins-base-libs-1.0.6-1 gstreamer-1.0.6-1 gtk-update-icon-cache-2.24.17-1 gtk2-2.24.17-1 harfbuzz-0.9.14-1 icu-51.1-1 imagemagick-6.8.4.6-1
intel-dri-9.1.1-1 kdeedu-kig-4.10.1-2 kdeedu-parley-4.10.1-2 lazarus-1.0.8-1 lib32-gcc-libs-4.8.0-1 lib32-glibc-2.17-4 lib32-gtk2-2.24.17-1
lib32-harfbuzz-0.9.14-1 lib32-icu-51.1-1 lib32-intel-dri-9.1.1-1 lib32-libcups-1.6.2-1 lib32-libdrm-2.4.43-1 lib32-libffi-3.0.13-1
lib32-libgcrypt-1.5.1-1 lib32-libltdl-2.4.2-8 lib32-libxi-1.7-1 lib32-mesa-9.1.1-1 lib32-mesa-libgl-9.1.1-1 lib32-sqlite-3.7.16-1 libcups-1.6.2-1
libdc1394-2.2.1-1 libdrm-2.4.43-1 libffi-3.0.13-1 libgcrypt-1.5.1-1 libkolabxml-0.8.3-2 libltdl-2.4.2-8 libmysqlclient-5.5.30-7 libproxy-0.4.11-1
libpulse-3.0-3 libreoffice-base-4.0.2-1 libreoffice-calc-4.0.2-1 libreoffice-common-4.0.2-1 libreoffice-draw-4.0.2-1
libreoffice-extension-nlpsolver-4.0.2-1 libreoffice-extension-presentation-minimizer-4.0.2-1 libreoffice-extension-report-builder-4.0.2-1
libreoffice-extension-wiki-publisher-4.0.2-1 libreoffice-impress-4.0.2-1 libreoffice-math-4.0.2-1 libreoffice-nb-4.0.2-1 libreoffice-sdk-4.0.2-1
libreoffice-writer-4.0.2-1 libsasl-2.1.23-10 libshairport-1.2.1.20121215-1 libssh-0.5.4-1 libtool-2.4.2-8 libwbclient-3.6.13-1 libxi-1.7-1
libxkbcommon-0.3.0-1 libzip-0.11-1 linux-3.8.5-1 linux-api-headers-3.8.4-1 lirc-utils-1:0.9.0-40 live-media-2013.04.01-1 lm_sensors-3.3.3-2
lua-5.2.2-1 mesa-9.1.1-1 mesa-libgl-9.1.1-1 mpg123-1.15.3-1 mysql-5.5.30-7 mysql-clients-5.5.30-7 ncurses-5.9-5 openssh-6.2p1-1
pacman-mirrorlist-20130323-1 perl-test-pod-1.46-1 polkit-0.110-1 poppler-0.22.2-1 poppler-glib-0.22.2-1 poppler-qt-0.22.2-1 postgresql-libs-9.2.4-1
povray-3.7.0.RC6-6 procps-ng-3.3.7-1 pyalpm-0.6-1 python-sip-4.14.5-1 python2-matplotlib-1.2.1-1 python2-sip-4.14.5-1 python2-six-1.3.0-1
qt3-1:3.3.8b-3 qt4-4.8.4-16 qtwebkit-2.3.0-1 raptor-2.0.9-2 rrdtool-1.4.7-5 ruby-2.0.0_p0-1 samba-3.6.13-1 sg3_utils-1.35-1 shadow-4.1.5.1-5
sip-4.14.5-1 smbclient-3.6.13-1 sqlite-3.7.16.1-1 systemd-198-2 upower-0.9.20-1 vim-7.3.875-1 vim-runtime-7.3.875-1 wayland-1.0.6-1 xbmc-12.1-5
xf86-input-evdev-2.8.0-1 xf86-input-keyboard-1.7.0-1 xf86-input-mouse-1.9.0-1 xf86-video-intel-2.21.5-1 xf86-video-vesa-2.3.2-3 xine-lib-1.2.2-8
xorg-server-1.14.0-2 xorg-server-common-1.14.0-2 xorg-server-xvfb-1.14.0-2 xproto-7.0.24-1 xulrunner-19.0.2-1

Total Download Size: 148.59 MiB
Total Installed Size: -1471.70 MiB
Net Upgrade Size: 30.08 MiB

:: Proceed with installation? [Y/n]
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Steps to Reproduce:

Just run -Syu