LLVM 21 apt packages unable to install on debian trixie due to unmet dependencies

[davidfiala]

For quite some time, clang21 installed fine via llvm.sh perfectly fine on trixie.

Recently, llvm.sh 21 all && apt-get install -y clang-21-doc libomp-21-doc llvm-21-doc installs broke on trixie, as the proof-of-concept below shows, due to:

• Depends: libstdc++-15-dev but it is not installable
• Depends: libgcc-15-dev but it is not installable
• Depends: libobjc-15-dev but it is not installable
• Depends: liblldb-21 but it is not going to be installed
• Depends: libxml2-16 (>= 2.14.1) but it is not installable
• Depends: python3-lldb-21 but it is not going to be installed

Possible guess is that llvm 21 is depping on packages available in debian unstable or testing, rather than stable packages.

Dockerfile.clangtest

# cat Dockerfile.clangtest | docker build --progress=plain -
FROM public.ecr.aws/docker/library/debian:trixie-slim

USER root
WORKDIR /root

RUN apt-get update && \
    apt-get dist-upgrade -y && \
    apt-get install -y curl gnupg lsb-release

ADD --checksum=sha256:70f8080fd855cb10cd79b140b8589a83f8a1f83d25b0bbf4436f55525425ac05 \
    --chmod=555 \
    https://apt.llvm.org/llvm.sh \
    /root/llvm.sh
RUN /root/llvm.sh 21 all && apt-get install -y clang-21-doc libomp-21-doc llvm-21-doc
RUN apt-get autoremove -y gcc g++
ENV PATH="/usr/lib/llvm-21/bin:$PATH"

#9 1.401 The following packages have unmet dependencies:
#9 1.401  clang-21 : Depends: libstdc++-15-dev but it is not installable
#9 1.401             Depends: libgcc-15-dev but it is not installable
#9 1.401             Depends: libobjc-15-dev but it is not installable
#9 1.401  clang-tools-21 : Depends: libxml2-16 (>= 2.14.1) but it is not installable
#9 1.401  libclang-21-dev : Depends: libstdc++-15-dev but it is not installable
#9 1.401                    Depends: libgcc-15-dev but it is not installable
#9 1.401                    Depends: libobjc-15-dev but it is not installable
#9 1.401  libclang-cpp21-dev : Depends: libstdc++-15-dev but it is not installable
#9 1.401                       Depends: libgcc-15-dev but it is not installable
#9 1.401  libllvm21 : Depends: libxml2-16 (>= 2.14.1) but it is not installable
#9 1.401  lldb-21 : Depends: liblldb-21 but it is not going to be installed
#9 1.401            Depends: libxml2-16 (>= 2.14.1) but it is not installable
#9 1.401            Depends: python3-lldb-21 but it is not going to be installed
#9 1.402 E: Unable to correct problems, you have held broken packages.
#9 1.402 E: The following information from --solver 3.0 may provide additional context:
#9 1.402    Unable to satisfy dependencies. Reached two conflicting decisions:
#9 1.402    1. libclang-21-dev:amd64=1:21.1.3~++20251015093208+bd9bc536b4ac-1~exp1~20251015093339.49 is selected for install
#9 1.402    2. libclang-21-dev:amd64 Depends libstdc++-15-dev
#9 1.402       but none of the choices are installable:
#9 1.402       [no choices]
#9 ERROR: process "/bin/sh -c /root/llvm.sh 21 all && apt-get install -y clang-21-doc libomp-21-doc llvm-21-doc" did not complete successfully: exit code: 100
------
 > [5/6] RUN /root/llvm.sh 21 all && apt-get install -y clang-21-doc libomp-21-doc llvm-21-doc:
1.401  lldb-21 : Depends: liblldb-21 but it is not going to be installed
1.401            Depends: libxml2-16 (>= 2.14.1) but it is not installable
1.401            Depends: python3-lldb-21 but it is not going to be installed

cat Dockerfile.clangtest | docker build --progress=plain - more detailed log in the expander:

Full llvm.sh execution with error

#9 [5/6] RUN /root/llvm.sh 21 all && apt-get install -y clang-21-doc libomp-21-doc llvm-21-doc
#9 0.140 + CURRENT_LLVM_STABLE=20
#9 0.140 + BASE_URL=http://apt.llvm.org
#9 0.140 + NEW_DEBIAN_DISTROS=("trixie" "unstable")
#9 0.140 + LLVM_VERSION=20
#9 0.140 + ALL=0
#9 0.140 ++ lsb_release -is
#9 0.144 + DISTRO=Debian
#9 0.144 ++ lsb_release -cs
#9 0.147 + VERSION_CODENAME=trixie
#9 0.147 ++ lsb_release -sr
#9 0.150 + VERSION=13
#9 0.150 + UBUNTU_CODENAME=
#9 0.150 + CODENAME_FROM_ARGUMENTS=
#9 0.150 + source /etc/os-release
#9 0.150 ++ PRETTY_NAME='Debian GNU/Linux 13 (trixie)'
#9 0.150 ++ NAME='Debian GNU/Linux'
#9 0.150 ++ VERSION_ID=13
#9 0.150 ++ VERSION='13 (trixie)'
#9 0.150 ++ VERSION_CODENAME=trixie
#9 0.150 ++ DEBIAN_VERSION_FULL=13.1
#9 0.150 ++ ID=debian
#9 0.150 ++ HOME_URL=https://www.debian.org/
#9 0.150 ++ SUPPORT_URL=https://www.debian.org/support
#9 0.150 ++ BUG_REPORT_URL=https://bugs.debian.org/
#9 0.150 + DISTRO=debian
#9 0.150 + is_new_debian=0
#9 0.150 + [[ debian == \d\e\b\i\a\n ]]
#9 0.150 + for new_distro in "${NEW_DEBIAN_DISTROS[@]}"
#9 0.150 + [[ trixie == \t\r\i\x\i\e ]]
#9 0.150 + is_new_debian=1
#9 0.150 + break
#9 0.150 + needed_binaries=(lsb_release wget gpg)
#9 0.150 + [[ 1 -eq 0 ]]
#9 0.150 + missing_binaries=()
#9 0.150 + using_curl=
#9 0.150 + for binary in "${needed_binaries[@]}"
#9 0.150 + command -v lsb_release
#9 0.150 + for binary in "${needed_binaries[@]}"
#9 0.150 + command -v wget
#9 0.150 + [[ wget == \w\g\e\t ]]
#9 0.150 + command -v curl
#9 0.150 + using_curl=1
#9 0.150 + continue
#9 0.150 + for binary in "${needed_binaries[@]}"
#9 0.150 + command -v gpg
#9 0.150 + [[ 0 -gt 0 ]]
#9 0.151 + case ${DISTRO} in
#9 0.151 + [[ 13 (trixie) == \u\n\s\t\a\b\l\e ]]
#9 0.151 + [[ 13 (trixie) == \t\e\s\t\i\n\g ]]
#9 0.151 + [[ trixie == \t\r\i\x\i\e ]]
#9 0.151 + CODENAME=unstable
#9 0.151 + LINKNAME=
#9 0.151 + '[' 2 -ge 1 ']'
#9 0.151 + '[' 2 '!=' - ']'
#9 0.151 + '[' 21 '!=' all ']'
#9 0.151 + LLVM_VERSION=21
#9 0.151 + OPTIND=2
#9 0.151 + '[' 2 -ge 2 ']'
#9 0.151 + '[' all == all ']'
#9 0.151 + ALL=1
#9 0.151 + OPTIND=3
#9 0.151 + getopts :hm:n: arg
#9 0.151 + [[ 0 -ne 0 ]]
#9 0.151 + declare -A LLVM_VERSION_PATTERNS
#9 0.151 + LLVM_VERSION_PATTERNS[9]=-9
#9 0.151 + LLVM_VERSION_PATTERNS[10]=-10
#9 0.151 + LLVM_VERSION_PATTERNS[11]=-11
#9 0.151 + LLVM_VERSION_PATTERNS[12]=-12
#9 0.151 + LLVM_VERSION_PATTERNS[13]=-13
#9 0.151 + LLVM_VERSION_PATTERNS[14]=-14
#9 0.151 + LLVM_VERSION_PATTERNS[15]=-15
#9 0.151 + LLVM_VERSION_PATTERNS[16]=-16
#9 0.151 + LLVM_VERSION_PATTERNS[17]=-17
#9 0.151 + LLVM_VERSION_PATTERNS[18]=-18
#9 0.151 + LLVM_VERSION_PATTERNS[19]=-19
#9 0.151 + LLVM_VERSION_PATTERNS[20]=-20
#9 0.151 + LLVM_VERSION_PATTERNS[21]=-21
#9 0.151 + LLVM_VERSION_PATTERNS[22]=
#9 0.151 + '[' '!' _ ']'
#9 0.151 + LLVM_VERSION_STRING=-21
#9 0.151 + [[ -n unstable ]]
#9 0.151 + REPO_NAME='deb http://apt.llvm.org/unstable/  llvm-toolchain-21 main'
#9 0.151 + wget -q --method=HEAD http://apt.llvm.org/unstable
#9 0.151 + curl -sSLI -XHEAD http://apt.llvm.org/unstable
#9 0.322 + [[ ! -f /etc/apt/trusted.gpg.d/apt.llvm.org.asc ]]
#9 0.322 + [[ -z 1 ]]
#9 0.323 + curl -sSL https://apt.llvm.org/llvm-snapshot.gpg.key
#9 0.323 + tee /etc/apt/trusted.gpg.d/apt.llvm.org.asc
#9 0.416 -----BEGIN PGP PUBLIC KEY BLOCK-----
#9 0.416 Version: GnuPG v1.4.12 (GNU/Linux)
#9 0.416
#9 0.416 mQINBFE9lCwBEADi0WUAApM/mgHJRU8lVkkw0CHsZNpqaQDNaHefD6Rw3S4LxNmM
#9 0.416 EZaOTkhP200XZM8lVdbfUW9xSjA3oPldc1HG26NjbqqCmWpdo2fb+r7VmU2dq3NM
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#9 0.416 G88bBXJAcPZnTSKu9I2c6KY4iRNbvRz4i+ZdwwZtdW4nSdl2792L7Sl7Nc44uLL/
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#9 0.416 wpmnF1OKyI2Kof2rm4BFwfSWuf8Fvh7kDMRLHv+MlnK/7j/BNpKdozXxLcwoFBmn
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#9 0.416 MWd8hnoUKhMeZ9TNmo+8CpsAtXZcBho0zPGz/R8NlJhAWpdAZ1CmcPo83EW86Yq7
#9 0.416 BxQUKnNHcwj2ebkCDQRRPZQsARAA4jxYmbTHwmMjqSizlMJYNuGOpIidEdx9zQ5g
#9 0.416 zOr431/VfWq4S+VhMDhs15j9lyml0y4ok215VRFwrAREDg6UPMr7ajLmBQGau0Fc
#9 0.416 bvZJ90l4NjXp5p0NEE/qOb9UEHT7EGkEhaZ1ekkWFTWCgsy7rRXfZLxB6sk7pzLC
#9 0.416 DshyW3zjIakWAnpQ5j5obiDy708pReAuGB94NSyb1HoW/xGsGgvvCw4r0w3xPStw
#9 0.416 F1PhmScE6NTBIfLliea3pl8vhKPlCh54Hk7I8QGjo1ETlRP4Qll1ZxHJ8u25f/ta
#9 0.416 RES2Aw8Hi7j0EVcZ6MT9JWTI83yUcnUlZPZS2HyeWcUj+8nUC8W4N8An+aNps9l/
#9 0.416 21inIl2TbGo3Yn1JQLnA1YCoGwC34g8QZTJhElEQBN0X29ayWW6OdFx8MDvllbBV
#9 0.416 ymmKq2lK1U55mQTfDli7S3vfGz9Gp/oQwZ8bQpOeUkc5hbZszYwP4RX+68xDPfn+
#9 0.416 M9udl+qW9wu+LyePbW6HX90LmkhNkkY2ZzUPRPDHZANU5btaPXc2H7edX4y4maQa
#9 0.416 xenqD0lGh9LGz/mps4HEZtCI5CY8o0uCMF3lT0XfXhuLksr7Pxv57yue8LLTItOJ
#9 0.416 d9Hmzp9G97SRYYeqU+8lyNXtU2PdrLLq7QHkzrsloG78lCpQcalHGACJzrlUWVP/
#9 0.416 fN3Ht3kAEQEAAYkCHwQYAQIACQUCUT2ULAIbDAAKCRAVz00Yr090IbhWEADbr50X
#9 0.416 OEXMIMGRLe+YMjeMX9NG4jxs0jZaWHc/WrGR+CCSUb9r6aPXeLo+45949uEfdSsB
#9 0.416 pbaEdNWxF5Vr1CSjuO5siIlgDjmT655voXo67xVpEN4HhMrxugDJfCa6z97P0+ML
#9 0.416 PdDxim57uNqkam9XIq9hKQaurxMAECDPmlEXI4QT3eu5qw5/knMzDMZj4Vi6hovL
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#9 0.416 oVQwtPNAQD6Cj7EaA2xdZYLJ7/jW6yiPu98FFWP74FN2dlyEA2uVziLsfBrgpS4l
#9 0.416 tVOlrO2YzkkqUGrybzbLpj6eeHx+Cd7wcjI8CalsqtL6cG8cUEjtWQUHyTbQWAgG
#9 0.416 5VPEgIAVhJ6RTZ26i/G+4J8neKyRs4vz+57UGwY6zI4AB1ZcWGEE3Bf+CDEDgmnP
#9 0.416 LSwbnHefK9IljT9XU98PelSryUO/5UPw7leE0akXKB4DtekToO226px1VnGp3Bov
#9 0.416 1GBGvpHvL2WizEwdk+nfk8LtrLzej+9FtIcq3uIrYnsac47Pf7p0otcFeTJTjSq3
#9 0.416 krCaoG4Hx0zGQG2ZFpHrSrZTVy6lxvIdfi0beMgY6h78p6M9eYZHQHc02DjFkQXN
#9 0.416 bXb5c6gCHESH5PXwPU4jQEE7Ib9J6sbk7ZT2Mw==
#9 0.416 =j+4q
#9 0.416 -----END PGP PUBLIC KEY BLOCK-----
#9 0.422 ++ apt-key list
#9 0.422 ++ grep -i llvm
#9 0.425 + [[ -z '' ]]
#9 0.425 + apt-key del AF4F7421
#9 0.425 /root/llvm.sh: line 199: apt-key: command not found
#9 0.425 + true
#9 0.426 + [[ trixie == \b\o\o\k\w\o\r\m ]]
#9 0.426 + [[ 1 -eq 1 ]]
#9 0.426 + SOURCES_FILE=/etc/apt/sources.list.d/http_apt_llvm_org_unstable_-trixie.sources
#9 0.426 + TEXT_TO_ADD='Types: deb
#9 0.426 Architectures: amd64 arm64
#9 0.426 Signed-By: /etc/apt/trusted.gpg.d/apt.llvm.org.asc
#9 0.426 URIs: http://apt.llvm.org/unstable/
#9 0.426 Suites: llvm-toolchain-21
#9 0.426 Components: main'
#9 0.426 + echo 'Types: deb
#9 0.426 Architectures: amd64 arm64
#9 0.426 Signed-By: /etc/apt/trusted.gpg.d/apt.llvm.org.asc
#9 0.426 URIs: http://apt.llvm.org/unstable/
#9 0.426 Suites: llvm-toolchain-21
#9 0.426 Components: main'
#9 0.426 + tee -a /etc/apt/sources.list.d/http_apt_llvm_org_unstable_-trixie.sources
#9 0.431 + apt-get update
#9 0.529 Hit:1 http://deb.debian.org/debian trixie InRelease
#9 0.534 Hit:3 http://deb.debian.org/debian trixie-updates InRelease
#9 0.560 Hit:4 http://deb.debian.org/debian-security trixie-security InRelease
#9 0.642 Get:2 https://apt.llvm.org/unstable llvm-toolchain-21 InRelease [6827 B]
#9 0.670 Get:5 https://apt.llvm.org/unstable llvm-toolchain-21/main amd64 Packages [21.8 kB]
#9 0.704 Get:6 https://apt.llvm.org/unstable llvm-toolchain-21/main arm64 Packages [21.6 kB]
#9 0.713 Fetched 50.3 kB in 0s (207 kB/s)
#9 0.713 Reading package lists...
#9 0.974 W: http://apt.llvm.org/unstable/dists/llvm-toolchain-21/InRelease: Policy will reject signature within a year, see --audit for details
#9 0.975 + PKG='clang-21 lldb-21 lld-21 clangd-21'
#9 0.975 + [[ 1 -eq 1 ]]
#9 0.975 + PKG='clang-21 lldb-21 lld-21 clangd-21 clang-tidy-21 clang-format-21 clang-tools-21 llvm-21-dev lld-21 lldb-21 llvm-21-tools libomp-21-dev libc++-21-dev libc++abi-21-dev libclang-common-21-dev libclang-21-dev libclang-cpp21-dev liblldb-21-dev libunwind-21-dev'
#9 0.975 + test 21 -gt 14
#9 0.975 + PKG='clang-21 lldb-21 lld-21 clangd-21 clang-tidy-21 clang-format-21 clang-tools-21 llvm-21-dev lld-21 lldb-21 llvm-21-tools libomp-21-dev libc++-21-dev libc++abi-21-dev libclang-common-21-dev libclang-21-dev libclang-cpp21-dev liblldb-21-dev libunwind-21-dev libclang-rt-21-dev libpolly-21-dev'
#9 0.975 + apt-get install -y clang-21 lldb-21 lld-21 clangd-21 clang-tidy-21 clang-format-21 clang-tools-21 llvm-21-dev lld-21 lldb-21 llvm-21-tools libomp-21-dev libc++-21-dev libc++abi-21-dev libclang-common-21-dev libclang-21-dev libclang-cpp21-dev liblldb-21-dev libunwind-21-dev libclang-rt-21-dev libpolly-21-dev
#9 0.993 Reading package lists...
#9 1.248 Building dependency tree...
#9 1.303 Reading state information...
#9 1.386 Solving dependencies...
#9 1.401 Some packages could not be installed. This may mean that you have
#9 1.401 requested an impossible situation or if you are using the unstable
#9 1.401 distribution that some required packages have not yet been created
#9 1.401 or been moved out of Incoming.
#9 1.401 The following information may help to resolve the situation:
#9 1.401
#9 1.401 The following packages have unmet dependencies:
#9 1.401  clang-21 : Depends: libstdc++-15-dev but it is not installable
#9 1.401             Depends: libgcc-15-dev but it is not installable
#9 1.401             Depends: libobjc-15-dev but it is not installable
#9 1.401  clang-tools-21 : Depends: libxml2-16 (>= 2.14.1) but it is not installable
#9 1.401  libclang-21-dev : Depends: libstdc++-15-dev but it is not installable
#9 1.401                    Depends: libgcc-15-dev but it is not installable
#9 1.401                    Depends: libobjc-15-dev but it is not installable
#9 1.401  libclang-cpp21-dev : Depends: libstdc++-15-dev but it is not installable
#9 1.401                       Depends: libgcc-15-dev but it is not installable
#9 1.401  libllvm21 : Depends: libxml2-16 (>= 2.14.1) but it is not installable
#9 1.401  lldb-21 : Depends: liblldb-21 but it is not going to be installed
#9 1.401            Depends: libxml2-16 (>= 2.14.1) but it is not installable
#9 1.401            Depends: python3-lldb-21 but it is not going to be installed
#9 1.402 E: Unable to correct problems, you have held broken packages.
#9 1.402 E: The following information from --solver 3.0 may provide additional context:
#9 1.402    Unable to satisfy dependencies. Reached two conflicting decisions:
#9 1.402    1. libclang-21-dev:amd64=1:21.1.3~++20251015093208+bd9bc536b4ac-1~exp1~20251015093339.49 is selected for install
#9 1.402    2. libclang-21-dev:amd64 Depends libstdc++-15-dev
#9 1.402       but none of the choices are installable:
#9 1.402       [no choices]
#9 ERROR: process "/bin/sh -c /root/llvm.sh 21 all && apt-get install -y clang-21-doc libomp-21-doc llvm-21-doc" did not complete successfully: exit code: 100
------
 > [5/6] RUN /root/llvm.sh 21 all && apt-get install -y clang-21-doc libomp-21-doc llvm-21-doc:
1.401  lldb-21 : Depends: liblldb-21 but it is not going to be installed
1.401            Depends: libxml2-16 (>= 2.14.1) but it is not installable
1.401            Depends: python3-lldb-21 but it is not going to be installed
1.402 E: Unable to correct problems, you have held broken packages.
1.402 E: The following information from --solver 3.0 may provide additional context:
1.402    Unable to satisfy dependencies. Reached two conflicting decisions:
1.402    1. libclang-21-dev:amd64=1:21.1.3~++20251015093208+bd9bc536b4ac-1~exp1~20251015093339.49 is selected for install
1.402    2. libclang-21-dev:amd64 Depends libstdc++-15-dev
1.402       but none of the choices are installable:
1.402       [no choices]
------
Dockerfile:15

[davidfiala]

Extra datapoint: Packaging for LLVM 20 works with RUN /root/llvm.sh 20 all

It's only LLVM 21 that appears(?) to have Debian testing or unstable dependencies mixed in, even for Trixie (current stable).

Is there any specific packaging maintainers to @ tag in? Thanks!

[ZhongRuoyu]

Mind having a look, @sylvestre?

Perhaps relatedly, in Debian Sid's repository (not apt.llvm.org):

# apt install libc++1 libc++-dev
Solving dependencies... Error!  
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

Unsatisfied dependencies:
 libc++-dev : Depends: libc++-19-dev (>= 19~) but it is not going to be installed
 libc++1 : Depends: libc++abi1 (>= 1:21.1.5-1) but it is not going to be installed
Error: Unable to satisfy dependencies. Reached two conflicting decisions:
   1. libc++-19-dev:amd64 Depends libc++1-19 (= 1:19.1.7-10.1)
      but none of the choices are installable:
      - libc++1-19:amd64 is not selected for install because:
        1. libc++1:amd64=1:21.1.5-1 is selected for install
        2. libc++1-19:amd64 Conflicts libc++-x.y
           [selected libc++1:amd64=1:21.1.5-1]
   2. libc++-19-dev:amd64 is selected for install because:
      1. libc++-dev:amd64=1:19.0-63 is selected for install
      2. libc++-dev:amd64 Depends libc++-19-dev (>= 19~)
# apt install libc++abi1 libc++abi-dev
Solving dependencies... Error!  
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

Unsatisfied dependencies:
 libc++abi-dev : Depends: libc++abi-19-dev (>= 19~) but it is not going to be installed
Error: Unable to satisfy dependencies. Reached two conflicting decisions:
   1. libc++abi-19-dev:amd64 Depends libc++abi1-19 (= 1:19.1.7-10.1)
      but none of the choices are installable:
      - libc++abi1-19:amd64 is not selected for install because:
        1. libc++abi1:amd64=1:21.1.5-1 is selected for install
        2. libc++abi1-19:amd64 Conflicts libc++abi-x.y
           [selected libc++abi1:amd64=1:21.1.5-1]
   2. libc++abi-19-dev:amd64 is selected for install because:
      1. libc++abi-dev:amd64=1:19.0-63 is selected for install
      2. libc++abi-dev:amd64 Depends libc++abi-19-dev (>= 19~)

[sylvestre]

sure, i will have a look

[jplehr]

I don't know if related, but I see this problem on debian testing:

$ sudo apt full-upgrade
You might want to run 'apt --fix-broken install' to correct these.
Unsatisfied dependencies:
 clang-21 : Depends: libllvm21 (= 1:21.1.5~++20251023083115+45afac62e373-1~exp1~20251023083259.57) but 1:21.1.5-1 is installed
            Depends: libclang-common-21-dev (= 1:21.1.5~++20251023083115+45afac62e373-1~exp1~20251023083259.57) but 1:21.1.5-1 is installed
            Depends: llvm-21-linker-tools (= 1:21.1.5~++20251023083115+45afac62e373-1~exp1~20251023083259.57) but 1:21.1.5-1 is installed
            Depends: libclang1-21 (= 1:21.1.5~++20251023083115+45afac62e373-1~exp1~20251023083259.57) but 1:21.1.5-1 is installed
Error: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).

And when I do apt --fix-broken install I get

Reading changelogs... Done
(Reading database ... 179964 files and directories currently installed.)
Preparing to unpack .../clang-tools-21_1%3a21.1.5-1_amd64.deb ...
Unpacking clang-tools-21 (1:21.1.5-1) over (1:21.1.5~++20251023083115+45afac62e373-1~exp1~20251023083259.57) ...
dpkg: error processing archive /var/cache/apt/archives/clang-tools-21_1%3a21.1.5-1_amd64.deb (--unpack):
 trying to overwrite '/usr/bin/asan_symbolize-21', which is also in package clang-21 (1:21.1.5~++20251023083115+45afac62e373-1~exp1~20251023083259.57)
Preparing to unpack .../clang-21_1%3a21.1.5-1_amd64.deb ...
Unpacking clang-21 (1:21.1.5-1) over (1:21.1.5~++20251023083115+45afac62e373-1~exp1~20251023083259.57) ...
dpkg: error processing archive /var/cache/apt/archives/clang-21_1%3a21.1.5-1_amd64.deb (--unpack):
 trying to overwrite '/usr/lib/llvm-21/bin/clang-scan-deps', which is also in package clang-tools-21 (1:21.1.5~++20251023083115+45afac62e373-1~exp1~20251023083259.57)
Errors were encountered while processing:
 /var/cache/apt/archives/clang-tools-21_1%3a21.1.5-1_amd64.deb
 /var/cache/apt/archives/clang-21_1%3a21.1.5-1_amd64.deb
Error: Sub-process /usr/bin/dpkg returned an error code (1)

Thank you for your time.

[lbonn]

I think it is due to this line https://github.com/opencollab/llvm-jenkins.debian.net/blob/0bbb0489a0dd6dc94adb6fb8dde77eeb8c3f66dd/llvm.sh#L83

trixie is no longer "testing", so probably the check should be updated to test for forky.

Possibly older toolchains (<21) have to be rebuilt, by using this patch I could not install llvm 20 on forky anymore.

[davidfiala]

Thank you @lbonn - this looks right. I thought I'd tried something like this back in October without success, but it clearly is working well now with your referenced commit. I appreciate it!