In start-bitbucket.sh the command for launching Bitbucket as another user looks like this:

$sucmd -l $BITBUCKET_USER -c "cd $(pwd);$PRGDIR/catalina.sh run $@"

In stop-bitbucket.sh it looks like this:

$sucmd -m $BITBUCKET_USER -c "$PRGDIR/shutdown.sh 60 -force $@"

By using -m instead of -l in stop-bitbucket.sh, shutdown.sh won't get the environment of BITBUCKET_USER and will therefore fail. Right now the workaround is having to define everything in setenv.sh.