37a38,79
> # A space-separated list of mounted repositories
> mounted_repos=
> 
> # Unmount all mounted repositories
> unmount_repos() {
>     
>     for _mounted_repo in $mounted_repos; do
>     
>         # If current repo directory is actually mounted
>         if fgrep -q "$_trimmed_chroot_path$_local_rep" < /etc/mtab; then
>             sudo umount "$_mounted_repo"
>         fi
>         # Remove the repo directory and any empty parent directories
>         sudo rmdir -p "$_mounted_repo" 2> /dev/null || :
>     done
>     exit
> }
> 
> # Mount a repository directory
> mount_repo() {
>     _chroot_path=$1
>     _local_rep=$2
>     
>     # Strip any meaningless trailing dots and slashes from the chroot path
>     _trimmed_chroot_path=$(echo $_chroot_path | sed 's|/\.\?$||')
>     
>     # If the local repo directory isn't already mounted
>     if ! fgrep -q "$_trimmed_chroot_path$_local_rep" < /etc/mtab; then
>         
>         # Make a mount dir within chroot and mount the local repo dir to it
>         sudo mkdir -p "$_trimmed_chroot_path$_local_rep"
>         sudo mount --bind "$_local_rep" "$_trimmed_chroot_path$_local_rep"
>         
>         # Add local repo to list of mounted repos
>         mounted_repos=`echo "$mounted_repos $_trimmed_chroot_path$_local_rep"`
>         
>         # Call unmount_repos to clean up the local repos when the script is 
>         # exited or interrupted
>         trap unmount_repos TERM INT EXIT
>     fi
> }
> 
60c102,121
< exec sudo chroot "$CHROOT_PATH" su -l -c "$ENV_EXPORT exec \$SHELL $SU_CMD" build
---
> # Mount every local repository in the chroot's sources.list file that doesn't 
> # exist in the chroot file system.
> 
> # All the local repositories mentioned in chroot's sources.list file
> local_repos=$(egrep -o '(file:[^[:space:]]+)' < "$CHROOT_PATH/etc/apt/sources.list" | sed 's/file://')
> 
> for local_repo in $local_repos; do
>     # If the directory doesn't exist in the chroot file system
>     if [ ! -e "$CHROOT_PATH$local_repo" ]; then
>         
>         # If the directory does exist in the exterior file system
>         if [ -d "$local_repo" ]; then
>             
>             # Make a mount dir and mount the exterior repository dir to it
>             mount_repo "$CHROOT_PATH" "$local_repo"
>         fi
>     fi
> done
> 
> sudo chroot "$CHROOT_PATH" su -l -c "$ENV_EXPORT exec \$SHELL $SU_CMD" build