Julia fails to launch without network connectivity

[tecosaur]

I'm looking at running Julia in a lightly sandboxed environment, and it seems like Juliaup's propensity to check for new versions is making that a bit difficult.

~$ sudo unshare --net --fork --mount-proc $(which julia) -- --project=@ -E 'println(22)'
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/RELEASEPREVIEWCHANNELDBVERSION`.
    3: error sending request for url (https://julialang-s3.julialang.org/juliaup/RELEASEPREVIEWCHANNELDBVERSION)
    4: client error (Connect)
    5: dns error: failed to lookup address information: Try again
    6: failed to lookup address information: Try again
Error: The Julia launcher failed to figure out which juliaup channel to use.

Linux, Juliaup 1.17.19

[tecosaur]

Ah, this looks like another version of #1184.

[tecosaur]

I'm not sure whether these two things are worth keeping separate:

1. A way to skip the startup check
2. Juliaup failing to update shouldn't prevent Julia from running

[davidanthoff]

I'm closing this as a duplicate of https://github.com/JuliaLang/juliaup/issues/1184.

Just to note, the error messages here are a bit misleading, I have an explanation of what is causing this in the linked issue.