convert: workaround for cvsps.cache under Windows
In non-cygwin environment, cvsps fails to create its cache directory and redirect its output to stderr. Just ignore the error and capture stderr as well.
#!/bin/sh
mkdir t
cd t
hg init
echo 1 > a
hg ci -qAm "first" -d "1000000 0"
hg cp a b
hg mv a c
echo 2 >> b
echo 2 >> c
hg ci -qAm "second" -d "1000000 0"
hg co -C 0
echo 0 > a
echo 1 >> a
hg ci -qAm "other" -d "1000000 0"
hg merge --debug
echo "-- b --"
cat b
echo "-- c --"
cat c