I've seen this bug with both 8.6.0 and testing (-amd64-netinst). I prepared the USB (8564:1000 Transcend Information, Inc. JetFlash) with sudo cp path/to/netinst.iso /dev/sdb I've never verified the images' integrity/authenticity.
The box has an Intel® Celeron® J1900 2.0 GHz processor and (according to 3.16.36 kernel) three I210 Gigabit [8086:1533] (rev 03) Ethernet ports, one [8086:0f35] Intel Z36xxx/Z37xxx USB xHCI, one [8086:0f34] Intel Z36xxx/Z37xxx USB EHCI. With 8.6.0 and the keyboard in the USB 3 socket, after selecting "Install" the keyboard stops working; moving it in one of the USB 2.0 socket fixes the issue.
After seeing the bug ("Select and install software - running dpkg - 12%") with 8.6.0, twice with testing, I retried with 8.6.0 (4th time) but choose the second mirror "ftp.linux.it" and watched the debug log most of the time. It hung on "Configuring apt - Scanning the mirror... - 33%". The keyboard stayed operative and the last debug line (ALT+F4) said "choose-mirror[1971]: DEBUG: command: wget -q http://ftp.linux.it/debian/dists/jessie/Release -O - | grep -E '^(Suite|Codename):'". This might be a problem with my network. After two and a half minutes it told me the mirror did not support jessie. I choose the standard mirror "ftp.it.debian.org" and the installation succeded. I retried (5th time) with 8.6.0, the keyboard was in one of the USB 2.0 sockets and stopped working after selecting "Install". Unplugging and plugging it in again (in any port) solved the issue. I replicated the "ftp.linux.it" hanging and again the installation succeded.
