setup: run hg with empty HGRCPATH for robustness.
Otherwise a bad hgrc file can make the version detection fail.
#!/bin/sh
echo "[extensions]" >> $HGRCPATH
echo "bookmarks=" >> $HGRCPATH
echo "mq=" >> $HGRCPATH
hg init
echo qqq>qqq.txt
echo % add file
hg add
echo % commit first revision
hg ci -m 1 -u user -d "1 0"
echo % set bookmark
hg book test
echo www>>qqq.txt
echo % commit second revision
hg ci -m 2 -u usr -d "1 0"
echo % set bookmark
hg book test2
echo % update to -2
hg update -r -2
echo eee>>qqq.txt
echo % commit new head
hg ci -m 3 -u user -d "1 0"
echo % bookmarks updated?
hg book
echo % strip to revision 1
hg strip 1 2>&1 | sed 's/\(saving bundle to \).*/\1/'
echo % list bookmarks
hg book