This just bit me on Debian 10, although it seems to affect only scripts run via in-target (i.e. `wget ...` works as expected, `in-target wget ...` doesn't).
Over the years the relevant lines have been changed slightly and moved to /lib/chroot-setup.sh: https://salsa.debian.org/installer-team/debian-installer-utils/-/blob/master/chroot-setup.sh#L136 RET=$(debconf-get mirror/protocol || true) if [ "$RET" = "http" ]; then RET=$(debconf-get mirror/http/proxy || true) if [ "$RET" ]; then http_proxy="$RET" export http_proxy fi fi As far as I can tell this is unnecessary for "in-target" APT to work, as proxy settings are written to /target/etc/apt/apt.conf already. And as others have pointed out, HTTP requests issued by any other program should not be affected by "mirror/http/proxy".