Bug: stacker grab has side-effects creates bin/

[smoser]

stacker version

v1.0.0-rc9

Describe the bug

'stacker grab' creates a 'bin/' directory in the current working directory.

To reproduce

Run the script below, it has output like:

$ bash ./go-test.sh
wrote /tmp/tt/stacker.yaml
$ stacker --work-dir=/tmp/tt/go-test.sh.d build --stacker-file=/tmp/tt/stacker.yaml --substitute=DOCKER_BASE=oci:/tmp/sync-oci.d:
preparing image build...
loading oci:/tmp/sync-oci.d:busybox:latest
Copying blob 3f4d90098f5b done  
Copying config 5ed23df91f done  
Writing manifest to image destination
Storing signatures
+ mkdir /output
+ echo foo
$ rm -Rf grab.d
$ mkdir grab.d
$ cd grab.d
$ stacker --work-dir=/tmp/tt/go-test.sh.d grab build:/output/file1.txt
found extra stuff from grab: tools

go-test.sh is:

#!/bin/bash
fail() { echo "$@" 1>&2; exit 1; }
r() { echo "$" "$@" 1>&2; "$@"; }

b=docker://
[ -d /tmp/sync-oci.d ] && b=oci:/tmp/sync-oci.d:
DOCKER_BASE=${DOCKER_BASE:-$b}

stackerfile="$PWD/stacker.yaml"
workd="$PWD/${0##*/}.d"
cat > "$stackerfile" <<"EOF"
build:
  from:
    type: docker
    url: ${{DOCKER_BASE:docker://}}busybox:latest
  build_only: true
  run: |
    mkdir /output
    echo foo > /output/file1.txt
EOF

echo "wrote $stackerfile" 1>&2
r stacker "--work-dir=$workd" build \
    "--stacker-file=$stackerfile" \
    "--substitute=DOCKER_BASE=${DOCKER_BASE}" ||
    fail "build failed"

r rm -Rf grab.d && r mkdir grab.d || fail "failed creating grab.d"
r cd grab.d || fail "failed cd grab.d"

r stacker "--work-dir=$workd" grab \
    build:/output/file1.txt

extra=""
for f in *; do
    case "$f" in 
        file1.txt) :;;
        *) extra="$extra $f";;
    esac
done

extra=${extra# }
[ -z "$extra" ] || fail "found extra stuff from grab: $extra"