`julia --version` behaves badly in an environment without network access

[Keno]

$ julia --version
Checking for new Julia versions
Error: Failed to run `run_command_add` from the `run_command_initial_setup_from_launcher` command.
Caused by:
    0: Failed to update versions db.
    1: Failed to download current version db version.
    2: Failed to download from url `https://julialang-s3.julialang.org/juliaup/RELEASECHANNELDBVERSION`.
    3: error sending request for url (https://julialang-s3.julialang.org/juliaup/RELEASECHANNELDBVERSION)
    4: client error (Connect)
    5: dns error: failed to lookup address information: Try again
    6: failed to lookup address information: Try again
Stack backtrace:
   0: juliaup::operations::download_juliaup_version
   1: juliaup::operations::update_version_db
   2: juliaup::command_add::run_command_add
   3: juliaup::main
   4: std::sys::backtrace::__rust_begin_short_backtrace
   5: main
Error: The Julia launcher failed to figure out which juliaup channel to use.
Stack backtrace:
   0: anyhow::error::::msg
   1: julialauncher::run_app
   2: julialauncher::main
   3: std::sys::backtrace::__rust_begin_short_backtrace
   4: main

I don't know that an auto-update failure should ever interfere with julia actually running. FWIW, the prior commands in this session were

juliaup add 1.12
juliaup default 1.12

So I also don't know why it doesn't know which channel to use.

[Keno]

I guess this is a dup of #1204 - but it's a pretty bad problem.

[davidanthoff]

I'm consolidating these issues over in #1184.

BUT, what you describe here does not entirely fit my analysis over there. Or was all of this somehow run in a sudo session?

[Keno]

Possibly run at uid 0 due to sandboxing.

[davidanthoff]

Would the juliaup add 1.12 and juliaup default 1.12 command also have been run as uid 0? If yes, then I'm confused what is happening. If they were run as a regular user, then I think my explanation over in #1184 would apply to this case as well.

[Keno]

I don't remember the exact setup.

[IanButterworth]

Isn't this fixed by #1258 and #1263

[KristofferC]

I guess the same thing would happen as in OP if you just ran it in interactive mode instead. So doesn't feel fixed fixed.

[davidanthoff]

No, all of those PRs tackle a completely different situation. The situation here is that the launcher can't find any Juliaup configuration and then tries to go through the initial setup process of creating the Juliaup config file, adding an initial channel etc. And that (on Linux and Mac) requires network access. The message Checking for new Julia versions is part of the initial setup process that is running there, but that code path is only triggered because the launcher is not finding any existing Juliaup configuration.

[IanButterworth]

Understood. The issue title perhaps could be clarified.