<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/58963>58963</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            apt.llvm.org frequently unreachable
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          Cireo
      </td>
    </tr>
</table>

<pre>
    When running the below periodically

    LLVM_VERSION=13
    sudo apt update
    # Handle [ENTER] prompt of add-repository
    echo | sudo add-apt-repository ppa:ubuntu-toolchain-r/test
    wget https://apt.llvm.org/llvm.sh -O /tmp/llvm.sh
    chmod +x /tmp/llvm.sh
    sudo /tmp/llvm.sh "${LLVM_VERSION}"

I see frequent (5-10%) failures with lines like

```
Failed to fetch http://apt.llvm.org/....deb  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
```

In particular, I saw this three times in a row today (tried a few hours apart).

Is this a known issue or a user error on my end?

<details>
  <summary>Log contents</summary>
```
+ sudo /tmp/llvm.sh 13
+ CURRENT_LLVM_STABLE=15
+ BASE_URL=http://apt.llvm.org/
+ needed_binaries=(lsb_release wget add-apt-repository gpg)
+ missing_binaries=()
+ for binary in "${needed_binaries[@]}"
+ which lsb_release
+ for binary in "${needed_binaries[@]}"
+ which wget
+ for binary in "${needed_binaries[@]}"
+ which add-apt-repository
+ for binary in "${needed_binaries[@]}"
+ which gpg
+ [[ 0 -gt 0 ]]
+ LLVM_VERSION=15
+ ALL=0
++ lsb_release -is
+ DISTRO=Ubuntu
++ lsb_release -sr
+ VERSION=18.04
+ UBUNTU_CODENAME=
+ CODENAME_FROM_ARGUMENTS=
+ source /etc/os-release
++ NAME=Ubuntu
++ VERSION='18.04.6 LTS (Bionic Beaver)'
++ ID=ubuntu
++ ID_LIKE=debian
++ PRETTY_NAME='Ubuntu 18.04.6 LTS'
++ VERSION_ID=18.04
++ HOME_URL=https://www.ubuntu.com/
++ SUPPORT_URL=https://help.ubuntu.com/
++ BUG_REPORT_URL=https://bugs.launchpad.net/ubuntu/
++ PRIVACY_POLICY_URL=https://www.ubuntu.com/legal/terms-and-policies/privacy-policy
++ VERSION_CODENAME=bionic
++ UBUNTU_CODENAME=bionic
+ DISTRO=ubuntu
+ case ${DISTRO} in
+ [[ -n bionic ]]
+ CODENAME=bionic
+ [[ -n bionic ]]
+ LINKNAME=-bionic
+ '[' 1 -ge 1 ']'
+ '[' 1 '!=' - ']'
+ '[' 13 '!=' all ']'
+ LLVM_VERSION=13
+ OPTIND=2
+ '[' 1 -ge 2 ']'
+ getopts :hm:n: arg
+ [[ 0 -ne 0 ]]
+ declare -A LLVM_VERSION_PATTERNS
+ LLVM_VERSION_PATTERNS[9]=-9
+ LLVM_VERSION_PATTERNS[10]=-10
+ LLVM_VERSION_PATTERNS[11]=-11
+ LLVM_VERSION_PATTERNS[12]=-12
+ LLVM_VERSION_PATTERNS[13]=-13
+ LLVM_VERSION_PATTERNS[14]=-14
+ LLVM_VERSION_PATTERNS[15]=-15
+ LLVM_VERSION_PATTERNS[16]=
+ '[' '!' _ ']'
+ LLVM_VERSION_STRING=-13
+ [[ -n bionic ]]
+ REPO_NAME='deb http://apt.llvm.org/bionic/  llvm-toolchain-bionic-13 main'
+ wget -q --method=HEAD http://apt.llvm.org/bionic
++ apt-key list
++ grep -i llvm
Warning: apt-key output should not be parsed (stdout is not a terminal)
+ [[ -z '' ]]
+ apt-key add -
+ wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key
--2022-11-13 19:31:09--  https://apt.llvm.org/llvm-snapshot.gpg.key
Resolving apt.llvm.org (apt.llvm.org)... 146.75.30.49, 2a04:4e42:77::561
Connecting to apt.llvm.org (apt.llvm.org)|146.75.30.49|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 3145 (3.1K) [application/octet-stream]
Saving to: ‘STDOUT’

  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable) Could not connect to apt.llvm.org:80 (146.75.30.49), connection timed out
Err:4 http://apt.llvm.org/bionic llvm-toolchain-bionic-13/main amd64 libclang-cpp13 amd64 1:13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66
  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
Err:5 http://apt.llvm.org/bionic llvm-toolchain-bionic-13/main amd64 libclang-common-13-dev amd64 1:13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66
  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
Err:6 http://apt.llvm.org/bionic llvm-toolchain-bionic-13/main amd64 llvm-13-linker-tools amd64 1:13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66
  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
Err:7 http://apt.llvm.org/bionic llvm-toolchain-bionic-13/main amd64 libclang1-13 amd64 1:13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66
  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
Err:8 http://apt.llvm.org/bionic llvm-toolchain-bionic-13/main amd64 clang-13 amd64 1:13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66
  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
Err:9 http://apt.llvm.org/bionic llvm-toolchain-bionic-13/main amd64 clangd-13 amd64 1:13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66
  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
Err:10 http://apt.llvm.org/bionic llvm-toolchain-bionic-13/main amd64 liblldb-13 amd64 1:13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66
  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
Err:11 http://apt.llvm.org/bionic llvm-toolchain-bionic-13/main amd64 lld-13 amd64 1:13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66
  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
Err:12 http://apt.llvm.org/bionic llvm-toolchain-bionic-13/main amd64 llvm-13-runtime amd64 1:13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66
  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
Err:13 http://apt.llvm.org/bionic llvm-toolchain-bionic-13/main amd64 llvm-13 amd64 1:13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66
  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
Err:14 http://apt.llvm.org/bionic llvm-toolchain-bionic-13/main amd64 llvm-13-tools amd64 1:13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66
  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
Err:15 http://apt.llvm.org/bionic llvm-toolchain-bionic-13/main amd64 llvm-13-dev amd64 1:13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66
  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
Err:16 http://apt.llvm.org/bionic llvm-toolchain-bionic-13/main amd64 python3-lldb-13 amd64 1:13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66
  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
Err:17 http://apt.llvm.org/bionic llvm-toolchain-bionic-13/main amd64 lldb-13 amd64 1:13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66
  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
Fetched 5248 kB in 30s (173 kB/s)
E: Failed to fetch http://apt.llvm.org/bionic/pool/main/l/llvm-toolchain-13/libllvm13_13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66_amd64.deb  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable) Could not connect to apt.llvm.org:80 (146.75.30.49), connection timed out
E: Failed to fetch http://apt.llvm.org/bionic/pool/main/l/llvm-toolchain-13/libclang-cpp13_13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66_amd64.deb  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
E: Failed to fetch http://apt.llvm.org/bionic/pool/main/l/llvm-toolchain-13/libclang-common-13-dev_13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66_amd64.deb  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
E: Failed to fetch http://apt.llvm.org/bionic/pool/main/l/llvm-toolchain-13/llvm-13-linker-tools_13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66_amd64.deb  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
E: Failed to fetch http://apt.llvm.org/bionic/pool/main/l/llvm-toolchain-13/libclang1-13_13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66_amd64.deb  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
E: Failed to fetch http://apt.llvm.org/bionic/pool/main/l/llvm-toolchain-13/clang-13_13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66_amd64.deb  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
E: Failed to fetch http://apt.llvm.org/bionic/pool/main/l/llvm-toolchain-13/clangd-13_13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66_amd64.deb  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
E: Failed to fetch http://apt.llvm.org/bionic/pool/main/l/llvm-toolchain-13/liblldb-13_13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66_amd64.deb  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
E: Failed to fetch http://apt.llvm.org/bionic/pool/main/l/llvm-toolchain-13/lld-13_13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66_amd64.deb  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
E: Failed to fetch http://apt.llvm.org/bionic/pool/main/l/llvm-toolchain-13/llvm-13-runtime_13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66_amd64.deb  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
E: Failed to fetch http://apt.llvm.org/bionic/pool/main/l/llvm-toolchain-13/llvm-13_13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66_amd64.deb  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
E: Failed to fetch http://apt.llvm.org/bionic/pool/main/l/llvm-toolchain-13/llvm-13-tools_13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66_amd64.deb  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
E: Failed to fetch http://apt.llvm.org/bionic/pool/main/l/llvm-toolchain-13/llvm-13-dev_13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66_amd64.deb  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
E: Failed to fetch http://apt.llvm.org/bionic/pool/main/l/llvm-toolchain-13/python3-lldb-13_13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66_amd64.deb  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
E: Failed to fetch http://apt.llvm.org/bionic/pool/main/l/llvm-toolchain-13/lldb-13_13.0.1~++20220120110844+75e33f71c2da-1~exp1~20220120230854.66_amd64.deb  Cannot initiate the connection to apt.llvm.org:80 (2a04:4e42:77::561). - connect (101: Network is unreachable)
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
Error: Process completed with exit code 100.
```
</details>
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJztW1tz4joS_jXOi8qULxjDAw_cMkMNCSkCc-o8UbItsDe27GPLYdhfv92-xDYhl914dk8tUBRgqbvV-tQtdQvJCp3j8A-XcRKnnHt8T4TLiMX88EAiFnuh49nU94-SMpWUUf5J4LVY_Lzb_pytHufLe0mfqnpVlaROSGgkSBo5VLCqQtJ08p1yx2dEMsaz-_VsJRlTEsVhANThjlDHkWMWhYknwvhYMTLbDYlkTgrRQAXia5Qkiqikj1Ir5SKVRRj6tks9LseSditYIipJhz0TxBUiSoAeauENojq-_xx0wngPj9nPxCXykiB3EFVllRjbDUIH6se_3iHKlD2thgJN0rqSOW4gaE6xvIbxnCSMkV3M_koZF8DVN2RVkTRD0gZkRz0_jVlCDp5wie9x-Ol7T6wuQOopxTt7vAUW5hARkh0Ttpth8BYEHXg5zCJkQjkPBfG4JzwYycw07JBzZgsv5CiswamP-gpqqlGlCw9d1tXgyzSxHX1k9FTQvUPkUgSSqooKVeSeiUMYPxEvISmPGYXhs3wG5Gf7UiDESURj4dmpT2GgJwQgowfQEYQINwb0hBcAMB4nlMRgziJ06BEbFbEHUFBA4kDcMI0T6AZIQu0aDSS5MEqeeHjgoFySMhLGUJAmLCYsjuEBcAiOhHFH0m8b-OsThwlAHSxtVhoFFCZpEFAwbn22CPcIhYDxBZoJAF_Vne-3Nn7DqEr3Q4rJZrUC39pm9vW4Ho0XM3RQo6IYjx5n281qAcXvmUHFwBlzmLO1PE4BOlAWrLXvJ9Y2Zj6jCcvd6oxf7qN9NYggKAAMYY45kdQg2QGmWfURR-7FW05VMMZSV4HZo-E5wH5wPbDumm4tS8aetizyNW4tN4Cj8FKEtMaYKETeC_hEJni_VJ_O6zWzGS3QYipbxLK6EcheUhFP54_r1RLoN9mk_DZTEldMtXb7HZhDXio24839erOdLKez-9Ed2nPN3ovC7e1qebcdrb5t7sD8Hxs0CXi5zdBvYPKDzzCRT80DyQrZZ1SuNJM0M1Ou0yOL9SNOJ2OYCz2bjBl9ZjHasmY2eOdTYEtfy5xPt4v5D2wQJluP8kblw2q2Xv-5LXurmblSpNb2aTuFjtusvSaAWP19eVf3-moBPBwOnVy9jh0GdcdHtsfNw8NytT7L6TI_eod1vPm2Xc3e5LbSfdLxacptN6JOh4NjabcFTieSHlbzn6PJn9uH5WIOX5_qhc_21M8CgDhIZAg75Cj0PRvdRbuNYu-Z2se86HgWxpqxWdkIN6heW-QJUeUBJ0NPbLT73I8LGnMK3v3KRWVOcpmvnPSdVj_kXczvfxS88itmsCjg10yiwvTA4DMrmdYtrUGEvzU1N1BY2N-n1pvkEFWeY3gjsMSq5cN6fo_Grb2tsnZOJszZYSQSWH5HbgAfHGMOGp-dFTk7Mys6zIYgA2arUUO_7cNoDUHs_eN59atqYzxAeQD54GNSVSloVeUTxGpJrH6CWCuJtU8Q6yWx_gnibknc_QSxURIbnyDu5cTnhrywJ_i1_ciUIBJaze-_nfbnQ3fB-as2C2NY_F7MVHiUdksIltZykbwGGicBPDb0zKIn-S8iywETbgiR5PT7bDT9TEP1KQljiCd2hEwgEY2KPUQWsDpnGuUVf9AYc73MDQquMBVRKkgCAbHvEAz7LYYBdsIw0eknwgEKDNCxihKcVSH68BuxW4nmP_ORMV-hWTYGIQ-RTwFYwgzyYWomJ5xGoKToQFTTAVm5FFnWFE0DJ0CA1QFI0DGxUAayTP5joSuWhP4z5sR1HkSjKWMA-RJRu72OaXR0pdMdYDbydhKUyZ4UaRQm3OFH8iH1bYg3Jyi5q2O7RTLFnCJ3-b5eP5AsbUxgNCG3QGXogXpZW5A0RiFPGHJqikKWP3KuBeN74aI96GrXQBX0jvoDc00YUBpFsEpSzPkwdoLGhJwISNOCl8F9pM95V1CENNOkviIN-o_r6XKzLh9LQylyof99ckkmL7Zecr3VanN0swGu6wqJpoMelPdtFseo4Sf8981JAihwmiA0cHpd8GgL1h--l-0oAvvOC7Fvqt5ROqpkznJPRx9QVHirSr_bhQLTYLq-M1Vbc6iMdOxXhF8loaYrfQPCyd7fZ1DqEBq_A8IwCEIO9bLDni8Hyl6LUCIV4Od7_InFGX1yOUCa7dtktmhdDID99gDMPfqSwBu0DJ5zUeipSqvO6_uOdVn4qW2uIhdme1r7K3Cccgw9LwhEvXUQLwi8NjOSwgIvLPhT28xICggvKg1RW8xDoqNwQw55yMUtw23mIJcDHv735zKHGFq3T57G-IeqriQZv6lDAf4BXyGNAv-dQxMvO78RQF5gjNuL5RZjNRLZEGTh43Og6tvW8N5mY_h3Obnx2zbXfv_A1Pba_l9H57-NZX3T7YrplzA9s_t2RbQNK8VtuCuSX0Gy3I-7ovhlFJ0rjG1EWFlwe8XxawvO1RbbWrSLDbsrmC2AeQWxDYu8xo-tQXlNbb4I5MmG3hXMLy7bFwLihmNZBWIS4l9ise16z3jWe0ICerQY3m_Lzh_iWcP8Zhre5RHxMb9FJcs775dcXFB5ucszwzs-2MhDHNosSUDFIPKZgEHLuNgvD_e3HEZURSlvD53c2smu9lR3gW7YUO31-rqpDAbqjTPUnYE-oDfCEz4bNg4Clre__GO98zdp7A-bRxr3oEpqlefe8ZRnYRNRHP4DAIXH7PISnnw3-oOefuMOjYFqDzRrpw80x6Q7xeqqiu0wU905Sm-ndW98ajE_GWZHbTXODvn9J7xeYkxvvCHah6qqOlqIqnQsy-r3ta7ZZwob7AZU6ioMLNR_6c1NPMxUwlP_UImHVJOqkgLse85Y1hzIpylMBfFw4sUsvMkaHmaK_wuYFl3x">