If you successfully managed an installation with debian-installer, please take time to provide us with a report. The simplest way to do so is to install the reportbug package (apt install reportbug), configure reportbug as explained in Bahagi 8.4.2, “Sending E-Mails Outside The System”, and run reportbug installation-reports.

If you did not complete the install, you probably found a bug in debian-installer. To improve the installer it is necessary that we know about them, so please take the time to report them. You can use an installation report to report problems; if the install completely fails, see Bahagi 5.4.6, “Reporting Installation Problems”.