Current iteration of "clean, pull, and build a new rakudo, then reinstall modules" script

new-rakudo.sh

#!/bin/bash

# Save existing panda state
STATE_DIR=~/git/rakudo-current-lib/site/panda
STATE_FILE=$STATE_DIR/state

SAVE_DIR=~/.perl6
SAVE_FILE=$SAVE_DIR/panda-state.save

[[ -e $STATE_FILE ]] && [[ -e $SAVE_FILE ]] && cp -a $SAVE_FILE $SAVE_FILE.bak
[[ -e $STATE_FILE ]] && ( mkdir -p $SAVE_DIR; cp -a $STATE_FILE $SAVE_FILE )

# Clean out old rakudo
cd ~/git/rakudo-current/
make realclean
rm -rf install

# Pull and build a new rakudo; bail out if this doesn't work
git pull
perl Configure.pl --gen-parrot && make && make install || exit

# Fix up rakudo-current-lib
CURRENT_LIB=`./perl6 -e '%*CUSTOM_LIB<site> ~~ m{^(.*)\/<-[/]>+\/?$}; say ~$0'`
cd ~/git
rm rakudo-current-lib
ln -s $CURRENT_LIB rakudo-current-lib

# Restore panda state and reboostrap with a new panda
[[ -e $SAVE_FILE ]] && ( mkdir -p $STATE_DIR; cp -a $SAVE_FILE $STATE_FILE )
cd ~/git/panda
git pull
./rebootstrap.pl