Bug#869859: Please set Acquire::Retries default to >0

[Michael Stapelberg <stapelberg@debian.org>]

Source: apt
Severity: wishlist

Occasionally, networks (such as the internet) are unreliable. I have observed
many transient network failures, be it between my machines and the Debian mirror
network, or be it in the CDNs behind deb.debian.org. This causes pain in
many different scenarios; I’d like to provide just two recent examples:

• Scheduled software updates (think a cron job at night time) are delayed
  unnecessarily because the update fails due to a transient network hickup which
  isn’t retried.

• Continuous integration builds on platforms such as travis-ci.org fail due to
  transient network hickups, confusing users and making them click the retry
  button for the entire build, wasting time and resources.

AFAICT, apt currently never retries HTTP requests by default:

% grep -r Acquire::Retries apt-1.5\~beta1 
apt-1.5~beta1/apt-pkg/acquire-item.h:    *  Set from Acquire::Retries.
apt-1.5~beta1/apt-pkg/acquire-item.h:    *  Acquire::Retries.
apt-1.5~beta1/apt-pkg/acquire-item.cc:   Retries = _config->FindI("Acquire::Retries",0);
apt-1.5~beta1/apt-pkg/acquire-item.cc:   Retries = _config->FindI("Acquire::Retries",0);

We should increase the default value of 0 to, say, 3.

Thanks for considering,

-- Package-specific info:

-- (no /etc/apt/preferences present) --


-- (no /etc/apt/preferences.d/* present) --


-- (/etc/apt/sources.list present, but not submitted) --


-- (/etc/apt/sources.list.d/bazel.list present, but not submitted) --


-- (/etc/apt/sources.list.d/cc65.list present, but not submitted) --


-- (/etc/apt/sources.list.d/google-chrome.list present, but not submitted) --


-- (/etc/apt/sources.list.d/keybase.list present, but not submitted) --


-- System Information:
Debian Release: buster/sid
  APT prefers testing
  APT policy: (990, 'testing'), (500, 'unstable-debug'), (500, 'testing-debug'), (500, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386, armel, mipsel, arm64

Kernel: Linux 4.9.0-3-amd64 (SMP w/8 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

-- no debconf information