<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/57248>57248</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            apt.llvm.org Debian Stretch issues
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          licaon-kter
      </td>
    </tr>
</table>

<pre>
    `https://apt.llvm.org/` says to add:
> deb http://apt.llvm.org/stretch/ llvm-toolchain-stretch-15 main
> deb-src http://apt.llvm.org/stretch/ llvm-toolchain-stretch-15 main
```
# apt-get update
Hit:1 http://security.debian.org/debian-security stretch/updates InRelease
Ign:2 http://deb.debian.org/debian stretch InRelease
Hit:3 http://deb.debian.org/debian stretch-updates InRelease
Hit:4 http://deb.debian.org/debian stretch-backports-sloppy InRelease
Hit:5 http://deb.debian.org/debian stretch-backports InRelease
Hit:6 http://deb.debian.org/debian testing InRelease
Hit:7 http://deb.debian.org/debian stretch Release
Ign:8 https://apt.llvm.org/stretch llvm-toolchain-stretch-15 InRelease
Ign:10 https://apt.llvm.org/stretch llvm-toolchain-stretch-15 Release
Ign:11 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main amd64 Packages
Ign:11 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main amd64 Packages
Ign:12 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main i386 Packages
Ign:12 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main i386 Packages
Ign:13 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main all Packages
Ign:13 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main all Packages
Ign:14 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en
Ign:14 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en
Ign:15 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en_GB
Ign:15 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en_GB
Ign:11 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main amd64 Packages
Ign:11 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main amd64 Packages
Ign:12 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main i386 Packages
Ign:12 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main i386 Packages
Ign:13 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main all Packages
Ign:13 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main all Packages
Ign:14 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en
Ign:14 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en
Ign:15 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en_GB
Ign:15 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en_GB
Ign:11 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main amd64 Packages
Ign:11 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main amd64 Packages
Ign:12 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main i386 Packages
Ign:12 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main i386 Packages
Ign:13 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main all Packages
Ign:13 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main all Packages
Ign:14 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en
Ign:14 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en
Ign:15 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en_GB
Ign:15 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en_GB
Ign:11 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main amd64 Packages
Ign:11 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main amd64 Packages
Ign:12 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main i386 Packages
Ign:12 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main i386 Packages
Ign:13 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main all Packages
Ign:13 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main all Packages
Ign:14 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en
Ign:14 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en
Ign:15 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en_GB
Ign:15 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en_GB
Ign:11 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main amd64 Packages
Ign:11 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main amd64 Packages
Ign:12 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main i386 Packages
Ign:12 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main i386 Packages
Ign:13 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main all Packages
Ign:13 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main all Packages
Ign:14 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en
Ign:14 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en
Ign:15 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en_GB
Ign:15 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en_GB
Err:11 http://apt.llvm.org/stretch llvm-toolchain-stretch-15/main amd64 Packages
  404  Not Found
Ign:11 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main amd64 Packages
Ign:12 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main i386 Packages
Ign:13 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main all Packages
Ign:14 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en
Ign:15 https://apt.llvm.org/stretch llvm-toolchain-stretch-15/main Translation-en_GB
Reading package lists...
W: The repository 'http://apt.llvm.org/stretch llvm-toolchain-stretch-15 Release' does not have a Release file.
E: Failed to fetch http://apt.llvm.org/stretch/dists/llvm-toolchain-stretch-15/main/binary-amd64/Packages  404  Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.
```

So looking at the folder structure https://apt.llvm.org/stretch/pool/main/l/ there's no actual `15` ok, so let me redo
> deb http://apt.llvm.org/stretch/ llvm-toolchain-stretch main
> deb-src http://apt.llvm.org/stretch/ llvm-toolchain-stretch main

...this updates fine.

Ok, now to install:
```
# sudo apt-get install -y --no-install-recommends clang-15 lldb-15 lld-15 clangd-15 libc++-15-dev libc++1-15 libc++abi-15-dev libc++abi1-15
Reading package lists...
Building dependency tree...
Reading state information...
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:

The following packages have unmet dependencies:
 clang-15 : Depends: libstdc++-7-dev but it is not installable
            Depends: libgcc-7-dev but it is not installable
            Depends: libobjc-7-dev but it is not installable
E: Unable to correct problems, you have held broken packages.
```

Umm, there are no such package for Stretch, eg. https://packages.debian.org/search?suite=all&arch=amd64&searchon=names&keywords=libstdc%2B%2B-7-dev

</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJztWVtz4jYU_jXwcsaMscHAAw-7S9Lmpe3sZfrYka1j0EaWWElOyr_vkXxJyJKU3ZD2xRkPtnX5zu37DhmUa35Yj7J459zejtJ3o-SaLrZ3Eynvqok2Wz-SxWDZwYLTwDj3y-LNKH43Sq-AYw5-83N7rTPoih09gR-NnNay2DGhonYmms6hovcjyMia4qKwWdxezWuSAgFGW3RQ7zlz2Iz_KhwZnB5btljURrjDhPwSTLUONC9RNwkPDjWAFm7UR5TIbIt9s1UEmRxjE8op2A7tKUbjX_pDGNEz_jRYsx_Dyllxu9fG2chKvd8fToPOfxL0NFp2HhqF6ITansZY_FjaTxRuCS9KpNv5PBlP0mEavxb2FOj0HOk8j0lrvHKAVTybwR9UHbZFe8LCz7t9honkMkGIdJm9ZOD1MTxvIb1QHaR8Cf8CVXjOwOwyAXw2TFnJnNAqQnXCwutDeMHE_C2C-OuX9yeMXDqOp1YGYQ_CHoQ9CHsQ9iDsQdiDsAdhD8IehD0IexD2IOxB2K-0cmXMGwsbYBbPAH7TDq51rfj_I_e3V-Obq-U_4PKb0ewjMu5_p9434YEU1tnJZNLM_klm4fMOweBeW-G0OcAoWbyKkv1vxMkCuEYLigi4Y3cIrJuCUkhsXbjyLlwzGuD-wKcM4OedxXAfC93_LTd0y4Vi5hAFttJrV-zTEgkufdIVglAc_w7eWih7H7m-V1IzPvGpOzSx5YjE1K3SBvko-QDagJYctKKdtaV9QllHtZicPiEKn580SK1vfbmYA0dlKQkDjT8oqAtXGzyLK_S0p2Q8BO8fPZzxNfH1AEZoTALZpyRlMehb77Ml--ig8nTg-oKHbm9x4vYYM3wSqd1OWOgOoEqhOo41n7-HIJW-9zX05SDZj_rDxey7Iztbc92f27XrITpAFCkdte-RwUJXFSpuoZBMbb0ApOR5e_e3MB6epMiLUfKeLnqLON49GpkeL2C5-H4NDfpl5yj7fS1kmOa4J-9QFQegxGG_oNtOYThP9FKbKnSPfkVQwL5TSqFr4rPXco5dNjBIgHJesQPRxh-L7Yi5B10HUTQwBr_VSNznQPOioj5jRS4RqN3UwaDXiijDLkYUr613y7O_9lZoaYPj1W5EXoctwY7VgarfakF8ffA06NE7ekDX6LIwSEG26iZrYbDSd7RL1w50CTeKykh229A_N9qT-t778ig5IdIdyr3nkEGrJdnyvvbRPDDqBNKxj7WqyMO-QAJtv_mBTL4XbcISP-vJYB3vWLQIBKGcgKCrabVtbR4SB4_-jpG2RfFaCJ1_PRMjdNUvyg_45BXakHYc7I2mkcp6bXbE8RnmkBt9S3XqcvZS5_xSVX5_6HGBRNTjbE1NohMHFRA-dS3lA-B28qSV9laODmotMkM70mtbC4ejdONbRpI1g5v22yRrVvnSbxSrqIpJdouHe218ljZ9xea-ZvOuao3jY1xPsyxeTReLVTrm65Sv0hUbO-Ekrh-3REp7ODNug6AsW1LVuDZyfRzIVrhdnU-Izu03Y_cFSYn-Sgmn12YvPcwXyWw53q0xx4LHLF3gcjnPyzSNp5wvy7xcxPNpks_GVEaUdj2aUwSJwvvGPD2P5puxWCdxksTL6Wo6i9NpOilXRZGuZiVmZYxFkY1mMVK3ln0wY7MOLuX11tJk07n6SUYNYqsQgznCZ7XbadohCkb_29w6NONgfh3c_wdPz0vn">