Bug#1111473: apt search tries to use color in pager but sometimes fails
Package: apt
Version: 3.1.4
Severity: minor
Dear Maintainer,
Let me start by saying I do not know where the problem exists, it may be
"apt" or it may be in the pager "less".
I noticed this on an upgrade from Bookworm to Trixie.
I then upgraded this test system to "unstable" to confirm that the problem is
still present.
Whenever I did an "apt search xxx", the listing would show the escape code
sequence rather than the expected colour change, and the listing was
monochrome.
On Bookworm, apt sends output directly to the terminal, while the
version in Trixie uses the default pager. Top shows it runs "pager"
(linked to "less" on my systems) but the command line shows no args even
under /proc/nnn/cmdline.
Other colorised features are still working as expected (bash PS1, ls-color, vim)
The problem occurs with different terminal characteristics, both on a VM
desktop running Xfce as well as headless VMs running server code. Tested on:
"xterm" in xterm and uxterm
"xterm-256color" in gnome terminal
"putty-256color" in putty ssh terminal.
All gave the same problem.
I have identified the contributing factor, which is the presence of an
environment variable named LESS - for many years (I have
forgotten why) I maintained a default environment value of "LESS=-M".
When I removed the LESS environment value, the problem went away.
The mere existence of the LESS environment value causes the problem,
even an empty string.
The Less manual is not clear whether options passed using this env var
cause everything on the command line to be deleted, but that would be
illogical. However that seems to be the result.
If I explicitly pipe the output to "less" or "pager" then there is no colorisation
attempted, which is what I would expect.
I have other env vars related to less: namely LESSCHARSET (probably
redundant these days), LESSOPEN and
LESSCLOSE. Removing those made no difference.
The easy workaround is to remove the LESS env value in my shell rc.
-- Package-specific info:
-- apt-config dump --
APT "";
APT::Architecture "amd64";
APT::Build-Essential "";
APT::Build-Essential:: "build-essential";
APT::Install-Recommends "1";
APT::Install-Suggests "0";
APT::Key "";
APT::Key::Assert-Pubkey-Algo ">=rsa2048,ed25519,ed448,nistp256,nistp384,nistp512,brainpoolP256r1,brainpoolP320r1,brainpoolP384r1,brainpoolP512r1,secp256k1";
APT::Key::Assert-Pubkey-Algo::Next ">=rsa2048,ed25519,ed448,nistp256,nistp384,nistp512";
APT::Key::Assert-Pubkey-Algo::Future ">=rsa3072,ed25519,ed448";
APT::Sandbox "";
APT::Sandbox::User "_apt";
APT::NeverAutoRemove "";
APT::NeverAutoRemove:: "^firmware-linux.*";
APT::NeverAutoRemove:: "^linux-firmware$";
APT::NeverAutoRemove:: "^linux-image-[a-z0-9]*$";
APT::NeverAutoRemove:: "^linux-image-[a-z0-9]*-[a-z0-9]*$";
APT::VersionedKernelPackages "";
APT::VersionedKernelPackages:: "linux-.*";
APT::VersionedKernelPackages:: "kfreebsd-.*";
APT::VersionedKernelPackages:: "gnumach-.*";
APT::VersionedKernelPackages:: ".*-modules";
APT::VersionedKernelPackages:: ".*-kernel";
APT::Never-MarkAuto-Sections "";
APT::Never-MarkAuto-Sections:: "metapackages";
APT::Never-MarkAuto-Sections:: "tasks";
APT::Move-Autobit-Sections "";
APT::Move-Autobit-Sections:: "oldlibs";
APT::Architectures "";
APT::Architectures:: "amd64";
APT::Compressor "";
APT::Compressor::. "";
APT::Compressor::.::Name ".";
APT::Compressor::.::Extension "";
APT::Compressor::.::Binary "";
APT::Compressor::.::Cost "0";
APT::Compressor::zstd "";
APT::Compressor::zstd::Name "zstd";
APT::Compressor::zstd::Extension ".zst";
APT::Compressor::zstd::Binary "zstd";
APT::Compressor::zstd::Cost "60";
APT::Compressor::zstd::CompressArg "";
APT::Compressor::zstd::CompressArg:: "-6";
APT::Compressor::zstd::UncompressArg "";
APT::Compressor::zstd::UncompressArg:: "-d";
APT::Compressor::lz4 "";
APT::Compressor::lz4::Name "lz4";
APT::Compressor::lz4::Extension ".lz4";
APT::Compressor::lz4::Binary "false";
APT::Compressor::lz4::Cost "50";
APT::Compressor::gzip "";
APT::Compressor::gzip::Name "gzip";
APT::Compressor::gzip::Extension ".gz";
APT::Compressor::gzip::Binary "gzip";
APT::Compressor::gzip::Cost "100";
APT::Compressor::gzip::CompressArg "";
APT::Compressor::gzip::CompressArg:: "-6n";
APT::Compressor::gzip::UncompressArg "";
APT::Compressor::gzip::UncompressArg:: "-d";
APT::Compressor::xz "";
APT::Compressor::xz::Name "xz";
APT::Compressor::xz::Extension ".xz";
APT::Compressor::xz::Binary "xz";
APT::Compressor::xz::Cost "200";
APT::Compressor::xz::CompressArg "";
APT::Compressor::xz::CompressArg:: "-6";
APT::Compressor::xz::UncompressArg "";
APT::Compressor::xz::UncompressArg:: "-d";
APT::Compressor::bzip2 "";
APT::Compressor::bzip2::Name "bzip2";
APT::Compressor::bzip2::Extension ".bz2";
APT::Compressor::bzip2::Binary "bzip2";
APT::Compressor::bzip2::Cost "300";
APT::Compressor::bzip2::CompressArg "";
APT::Compressor::bzip2::CompressArg:: "-6";
APT::Compressor::bzip2::UncompressArg "";
APT::Compressor::bzip2::UncompressArg:: "-d";
APT::Compressor::lzma "";
APT::Compressor::lzma::Name "lzma";
APT::Compressor::lzma::Extension ".lzma";
APT::Compressor::lzma::Binary "xz";
APT::Compressor::lzma::Cost "400";
APT::Compressor::lzma::CompressArg "";
APT::Compressor::lzma::CompressArg:: "--format=lzma";
APT::Compressor::lzma::CompressArg:: "-6";
APT::Compressor::lzma::UncompressArg "";
APT::Compressor::lzma::UncompressArg:: "--format=lzma";
APT::Compressor::lzma::UncompressArg:: "-d";
Dir "/";
Dir::State "var/lib/apt";
Dir::State::lists "lists/";
Dir::State::cdroms "cdroms.list";
Dir::State::extended_states "extended_states";
Dir::State::status "/var/lib/dpkg/status";
Dir::Cache "var/cache/apt";
Dir::Cache::archives "archives/";
Dir::Cache::srcpkgcache "srcpkgcache.bin";
Dir::Cache::pkgcache "pkgcache.bin";
Dir::Etc "etc/apt";
Dir::Etc::sourcelist "sources.list";
Dir::Etc::sourceparts "sources.list.d";
Dir::Etc::main "apt.conf";
Dir::Etc::netrc "auth.conf";
Dir::Etc::netrcparts "auth.conf.d";
Dir::Etc::parts "apt.conf.d";
Dir::Etc::preferences "preferences";
Dir::Etc::preferencesparts "preferences.d";
Dir::Etc::trustedparts "trusted.gpg.d";
Dir::Boot "boot";
Dir::Usr "usr";
Dir::Bin "";
Dir::Bin::methods "/usr/lib/apt/methods";
Dir::Bin::solvers "";
Dir::Bin::solvers:: "/usr/lib/apt/solvers";
Dir::Bin::planners "";
Dir::Bin::planners:: "/usr/lib/apt/planners";
Dir::Bin::dpkg "/usr/bin/dpkg";
Dir::Bin::gzip "/bin/gzip";
Dir::Bin::bzip2 "/bin/bzip2";
Dir::Bin::xz "/usr/bin/xz";
Dir::Bin::lz4 "/usr/bin/lz4";
Dir::Bin::zstd "/usr/bin/zstd";
Dir::Bin::lzma "/usr/bin/xz";
Dir::Media "";
Dir::Media::MountPath "/media/apt";
Dir::Log "var/log/apt";
Dir::Log::Terminal "term.log";
Dir::Log::History "history.log";
Dir::Log::Planner "eipp.log.xz";
Dir::Ignore-Files-Silently "";
Dir::Ignore-Files-Silently:: "~$";
Dir::Ignore-Files-Silently:: "\.disabled$";
Dir::Ignore-Files-Silently:: "\.bak$";
Dir::Ignore-Files-Silently:: "\.dpkg-[a-z]+$";
Dir::Ignore-Files-Silently:: "\.ucf-[a-z]+$";
Dir::Ignore-Files-Silently:: "\.save$";
Dir::Ignore-Files-Silently:: "\.orig$";
Dir::Ignore-Files-Silently:: "\.distUpgrade$";
Acquire "";
Acquire::AllowInsecureRepositories "0";
Acquire::AllowWeakRepositories "0";
Acquire::AllowDowngradeToInsecureRepositories "0";
Acquire::cdrom "";
Acquire::cdrom::mount "/media/cdrom/";
Acquire::IndexTargets "";
Acquire::IndexTargets::deb "";
Acquire::IndexTargets::deb::Packages "";
Acquire::IndexTargets::deb::Packages::MetaKey "$(COMPONENT)/binary-$(ARCHITECTURE)/Packages";
Acquire::IndexTargets::deb::Packages::flatMetaKey "Packages";
Acquire::IndexTargets::deb::Packages::ShortDescription "Packages";
Acquire::IndexTargets::deb::Packages::Description "$(RELEASE)/$(COMPONENT) $(ARCHITECTURE) Packages";
Acquire::IndexTargets::deb::Packages::flatDescription "$(RELEASE) Packages";
Acquire::IndexTargets::deb::Packages::Optional "0";
Acquire::IndexTargets::deb::Translations "";
Acquire::IndexTargets::deb::Translations::MetaKey "$(COMPONENT)/i18n/Translation-$(LANGUAGE)";
Acquire::IndexTargets::deb::Translations::flatMetaKey "$(LANGUAGE)";
Acquire::IndexTargets::deb::Translations::ShortDescription "Translation-$(LANGUAGE)";
Acquire::IndexTargets::deb::Translations::Description "$(RELEASE)/$(COMPONENT) Translation-$(LANGUAGE)";
Acquire::IndexTargets::deb::Translations::flatDescription "$(RELEASE) Translation-$(LANGUAGE)";
Acquire::IndexTargets::deb-src "";
Acquire::IndexTargets::deb-src::Sources "";
Acquire::IndexTargets::deb-src::Sources::MetaKey "$(COMPONENT)/source/Sources";
Acquire::IndexTargets::deb-src::Sources::flatMetaKey "Sources";
Acquire::IndexTargets::deb-src::Sources::ShortDescription "Sources";
Acquire::IndexTargets::deb-src::Sources::Description "$(RELEASE)/$(COMPONENT) Sources";
Acquire::IndexTargets::deb-src::Sources::flatDescription "$(RELEASE) Sources";
Acquire::IndexTargets::deb-src::Sources::Optional "0";
Acquire::Changelogs "";
Acquire::Changelogs::URI "";
Acquire::Changelogs::URI::Origin "";
Acquire::Changelogs::URI::Origin::Debian "https://metadata.ftp-master.debian.org/changelogs/@CHANGEPATH@_changelog";;
Acquire::Changelogs::URI::Origin::Ubuntu "https://changelogs.ubuntu.com/changelogs/pool/@CHANGEPATH@/changelog";;
Acquire::Changelogs::AlwaysOnline "";
Acquire::Changelogs::AlwaysOnline::Origin "";
Acquire::Changelogs::AlwaysOnline::Origin::Ubuntu "1";
Acquire::Snapshots "";
Acquire::Snapshots::URI "";
Acquire::Snapshots::URI::Origin "";
Acquire::Snapshots::URI::Origin::Debian "https://snapshot.debian.org/archive/debian/@SNAPSHOTID@/";;
Acquire::Snapshots::URI::Origin::Ubuntu "https://snapshot.ubuntu.com/ubuntu/@SNAPSHOTID@/";;
Acquire::Snapshots::URI::Override "";
Acquire::Snapshots::URI::Override::Label "";
Acquire::Snapshots::URI::Override::Label::Debian-Security "https://snapshot.debian.org/archive/debian-security/@SNAPSHOTID@/";;
Acquire::Snapshots::URI::Host "";
Acquire::Snapshots::URI::Host::archive.ubuntu.com "https://snapshot.ubuntu.com/@PATH@/@SNAPSHOTID@/";;
Acquire::Snapshots::URI::Host::deb.debian.org "https://snapshot.debian.org/archive/@PATH@/@SNAPSHOTID@/";;
Acquire::Snapshots::URI::Host::.archive.ubuntu.com "https://snapshot.ubuntu.com/@PATH@/@SNAPSHOTID@/";;
Acquire::Snapshots::URI::Host::security.ubuntu.com "https://snapshot.ubuntu.com/@PATH@/@SNAPSHOTID@/";;
Acquire::Snapshots::URI::Host::ppa.launchpadcontent.net "https://snapshot.ppa.launchpadcontent.net/@PATH@/@SNAPSHOTID@/";;
Acquire::Snapshots::URI::Host::ppa.launchpad.net "https://snapshot.ppa.launchpadcontent.net/@PATH@/@SNAPSHOTID@/";;
Acquire::Languages "";
Acquire::Languages:: "en";
Acquire::Languages:: "none";
Acquire::CompressionTypes "";
Acquire::CompressionTypes::xz "xz";
Acquire::CompressionTypes::bz2 "bzip2";
Acquire::CompressionTypes::lzma "lzma";
Acquire::CompressionTypes::gz "gzip";
Acquire::CompressionTypes::lz4 "lz4";
Acquire::CompressionTypes::zst "zstd";
DPkg "";
DPkg::Path "/usr/sbin:/usr/bin:/sbin:/bin";
DPkg::Pre-Install-Pkgs "";
DPkg::Pre-Install-Pkgs:: "/usr/bin/apt-listbugs apt";
DPkg::Pre-Install-Pkgs:: "/usr/sbin/dpkg-preconfigure --apt || true";
DPkg::Tools "";
DPkg::Tools::Options "";
DPkg::Tools::Options::/usr/bin/apt-listbugs "";
DPkg::Tools::Options::/usr/bin/apt-listbugs::Version "3";
DPkg::Tools::Options::/usr/bin/apt-listbugs::InfoFD "20";
AptListbugs "";
AptListbugs::Severities "critical,grave,serious";
Binary "apt-config";
Binary::apt-cdrom "";
Binary::apt-cdrom::APT "";
Binary::apt-cdrom::APT::Internal "";
Binary::apt-cdrom::APT::Internal::OpProgress "";
Binary::apt-cdrom::APT::Internal::OpProgress::EraseLines "0";
Binary::apt "";
Binary::apt::APT "";
Binary::apt::APT::Color "1";
Binary::apt::APT::Output-Version "30";
Binary::apt::APT::Cache "";
Binary::apt::APT::Cache::Show "";
Binary::apt::APT::Cache::Show::Version "2";
Binary::apt::APT::Cache::AllVersions "0";
Binary::apt::APT::Cache::ShowVirtuals "1";
Binary::apt::APT::Cache::Search "";
Binary::apt::APT::Cache::Search::Version "2";
Binary::apt::APT::Cache::ShowDependencyType "1";
Binary::apt::APT::Cache::ShowVersion "1";
Binary::apt::APT::Get "";
Binary::apt::APT::Get::Upgrade-Allow-New "1";
Binary::apt::APT::Get::Update "";
Binary::apt::APT::Get::Update::InteractiveReleaseInfoChanges "1";
Binary::apt::APT::Cmd "";
Binary::apt::APT::Cmd::Show-Update-Stats "1";
Binary::apt::APT::Cmd::Pattern-Only "1";
Binary::apt::APT::Keep-Downloaded-Packages "0";
Binary::apt::DPkg "";
Binary::apt::DPkg::Progress-Fancy "1";
Binary::apt::DPkg::Lock "";
Binary::apt::DPkg::Lock::Timeout "-1";
Binary::apt::Pager "1";
CommandLine "";
CommandLine::AsString "apt-config dump";
-- (no /etc/apt/preferences present) --
-- (no /etc/apt/preferences.d/* present) --
-- (no /etc/apt/sources.list present) --
-- /etc/apt/sources.list.d/debian.sources --
Types: deb deb-src
URIs: https://deb.debian.org/debian
Suites: testing testing-updates
Components: main non-free-firmware contrib non-free
Enabled: yes
Signed-By: /usr/share/keyrings/debian-archive-keyring.gpg
Types: deb deb-src
URIs: https://security.debian.org/debian-security
Suites: testing-security
Components: main non-free-firmware contrib non-free
Enabled: yes
Signed-By: /usr/share/keyrings/debian-archive-keyring.gpg
-- (/etc/apt/sources.list.d/ookla_speedtest-cli.list present, but not submitted) --
-- (/etc/apt/sources.list.d/weewx.list present, but not submitted) --
-- System Information:
Debian Release: forky/sid
APT prefers testing
APT policy: (500, 'testing')
Architecture: amd64 (x86_64)
Kernel: Linux 6.12.41+deb13-amd64 (SMP w/1 CPU thread; PREEMPT)
Locale: LANG=C, LC_CTYPE=C.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
Versions of packages apt depends on:
ii adduser 3.152
ii base-passwd 3.6.7
ii debian-archive-keyring 2025.1
ii libapt-pkg7.0 3.1.4
ii libc6 2.41-12
ii libgcc-s1 15.2.0-1
ii libseccomp2 2.6.0-2
ii libssl3t64 3.5.2-1
ii libstdc++6 15.2.0-1
ii libsystemd0 258~rc2-2
ii sqv 1.3.0-3
Versions of packages apt recommends:
ii ca-certificates 20250419
Versions of packages apt suggests:
pn apt-doc <none>
pn aptitude | synaptic | wajig <none>
pn dpkg-dev <none>
ii gnupg 2.4.8-2
pn powermgmt-base <none>
-- no debconf information
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