missing /usr/lib/liblzma.a during HEAD buildworld ?

[Luigi Rizzo]

Hi,
building HEAD on my laptop (stable/7 approx jun 2009)
fails with the following error:

sh /usr/home/luigi/FreeBSD/head/tools/install.sh -o root -g wheel -m 444  fr.ISO8859-1-s /home/luigi/FreeBSD/obj_head/usr/home/luigi/FreeBSD/head/tmp/legacy/usr/share/tmac/mdoc/fr.ISO8859-1
sh /usr/home/luigi/FreeBSD/head/tools/install.sh -o root -g wheel -m 444  ru.KOI8-R-s /home/luigi/FreeBSD/obj_head/usr/home/luigi/FreeBSD/head/tmp/legacy/usr/share/tmac/mdoc/ru.KOI8-R
===> usr.bin/ar (obj,depend,all,install)
make: don't know how to make /usr/lib/liblzma.a. Stop
*** Error code 2

Stop in /usr/home/luigi/FreeBSD/head.
*** Error code 1

The build apparently works fine on my desktop, still stable/7 from Sep.2009)

Any idea on what could be wrong ?

cheers
luigi