(OK) Android 6.0 (Marshmallow) Install apk - INSTALL_FAILED_INVALID_URI

must be under the root directory:

cd /
pm install /sdcard/Download/chrome51.apk

Success

root@x86_64:/ # pm list packages|grep chrome                                   
package:com.android.chrome
package:com.chrome.dev
root@x86_64:/ # pm uninstall com.chrome.dev