Than I really suggest you to prepare your chroot. Not only you're not messing with rootfs partition, you can back it up in your pc after it's ready and just copy it back in case of reflash.

You need the easy-chroot package installed: #apt-get install easy-chroot

Here it is how I have prepared mine:
Go to http://qole.org/files/maemo-sdk-v1_2.img.ext2.lzma to download the image archive.
http://tablets-dev.nokia.com/eula/index.php to get your personal token.
Extract the lmza file and copy the ext in MyDocs partition.
On n900 terminal:
cd /home/user/MyDocs
mkdir /floppy
qmount /home/user/MyDocs/maemo-sdk-v1_2.img.ext2 /floppy
mkdir /floppy/dev
mkdir /floppy/dev/pts
mkdir /floppy/dev/shm
mkdir /floppy/usr/share/X11
mkdir /floppy/usr/share/X11/xkb
mkdir /floppy/var/run/dbus
mkdir /floppy/var/lib/dbus
mkdir /floppy/var/run/pulse
cp /bin/busybox /floppy/bin
cp /etc/hosts /floppy/etc/hosts
cp /etc/ld.so.conf /floppy/etc/ld.so.conf
CHROOT=/floppy synchroot
echo "exit 101" > /floppy/usr/sbin/policy-rc.d
echo "deb http://repository.maemo.org/ fremantle/<your token code here> nokia-binaries" >> /floppy/etc/apt/sources.list
qumount /floppy
mkdir /sdk
qchroot /home/user/MyDocs/maemo-sdk-v1_2.img.ext2 /sdk
apt-get update
apt-get install nokia-binaries (it will take more than 1hour at least)
apt-get install libqt4-dev
apt-get install libqtm-dev
apt-get install locale-resolver-data
apt-get install posix-locales
apt-get install libi18n-locale-resolver0

and you're done. Following this, qmake is for armel architecture.

http://maemo.org/packages/package_in...9-0maemo1+0m5/ should be the armel package for qmake btw.