actual_env_command=`python3 ./pinch.py update --dry-run --profile /path/to/profile "$conf"`
-expected_env_command_RE='^nix-env --profile /path/to/profile --show-trace --file '\''<nix/unpack-channel.nix>'\'' --install --from-expression '\''f: f \{ name = "(repo-[0-9]{10}-[0-9a-f]{11})"; channelName = "foo"; src = builtins.storePath "'"$NIX_STORE_DIR"'/.{32}-\1.tar.xz"; \}'\''$'
+expected_env_command_RE='^nix-env --profile /path/to/profile --show-trace --file '\''<nix/unpack-channel.nix>'\'' --install --remove-all -I pinch_tarball_for_(repo-[0-9]{10}-[0-9a-f]{11})=('"$NIX_STORE_DIR"'/.{32}-\1.tar.xz) --from-expression '\''f: f \{ name = "\1"; channelName = "foo"; src = builtins.storePath "\2"; \}'\''$'
if echo "$actual_env_command" | egrep "$expected_env_command_RE" > /dev/null;then
echo PASS