Fix get_debootstrap script

Now it extracts and calls the program properly, if it isn't already
installed.

Also, the script `debian/cleanup_everything` removes debootstrap and
both of the created Debian roots, returning the repository to the same
state it clones in as.

debian/cleanup_everything

@@ -0,0 +1,32 @@
+#!/bin/sh
+
+if test `id -u` -ne 0
+then
+    echo "$0 must be run as root."
+    return
+fi
+
+if test -d test_environment
+then
+    # Call this script that automatically unmounts the mount points too.
+    ./destroy_environment
+fi
+
+if test -d clean_environment
+then
+    echo "Removing clean_environment"
+    rm -r clean_environment
+fi
+
+if test -d debootstrap
+then
+    echo "Removing debootstrap"
+    rm -r debootstrap
+fi
+
+if test -f debootstrap.tar.gz
+then
+    echo "Removing debootstrap.tar.gz"
+    rm debootstrap.tar.gz
+fi
+

debian/get_debootstrap

@@ -1,23 +1,33 @@
 #!/bin/sh
 
-# Finds debootstrap in $PATH, or the current directory, or download some
-# version of it if none is found.
+# Finds debootstrap in $PATH, or download some version of it if not found.
+# This script prefers to use local copies that are already downloaded, over
+# system-wide installations, in case you want to test on some specific
+# outdated version of debootstrap.
 
-IT_LOCAL=`pwd`/debootstrap/debootstrap
-if test -e "$IT_LOCAL"
+download_it() {
+    curl http://deb.debian.org/debian/pool/main/d/debootstrap/debootstrap_1.0.128+nmu2+deb12u2.tar.gz --output debootstrap.tar.gz
+    tar xf debootstrap.tar.gz && rm debootstrap.tar.gz
+}
+
+LOCALDIR=`pwd`/debootstrap
+if test -e "$LOCALDIR/debootstrap"
 then
-    IT="$IT_LOCAL"
-    echo "Found $IT in current directory"
+    echo "Found $LOCALDIR/debootstrap in current directory"
+
+    # Run debootstrap without installing it to the system.
+    DEBOOTSTRAP_DIR="$LOCALDIR" "$LOCALDIR/debootstrap" "$@"
 elif IT=`command -v debootstrap`
 then
     echo "Found $IT in PATH"
-else
-    echo "debootstrap not found. Downloading to $IT_LOCAL."
-    curl http://deb.debian.org/debian/pool/main/d/debootstrap/debootstrap_1.0.128+nmu2+deb12u2.tar.gz --output debootstrap.tar.gz
-    tar xf debootstrap.tar.gx
 
-    IT="$IT_LOCAL"
+    # Use the version of debootstrap that was already installed.
+    debootstrap "$@"
+else
+    echo "debootstrap not found. Downloading to $LOCALDIR."
+    download_it
+
+    # Run debootstrap without installing it to the system.
+    DEBOOTSTRAP_DIR="$LOCALDIR" "$LOCALDIR/debootstrap" "$@"
 fi
 
-# Run debootstrap.
-"$IT" "$@"