Cannot Operate Offline

[defndaines]

You cannot run elm-make or elm-repl without an Internet connection. Here is an example error:

$ elm-repl
Elm REPL 0.4.2 (Elm Platform 0.15.1)
  See usage examples at <https://github.com/elm-lang/elm-repl>
  Type :help for help, :exit to exit
> 4
failed with 'FailedConnectionException2 "package.elm-lang.org" 80 False getAddrInfo: does not exist (nodename nor servname provided, or not known)' when sending request to
    <http://package.elm-lang.org/all-packages?elm-package-version=0.5.1>

This appears to be the problem behind elm-lang/elm-make#34 and I encountered the problem just using the REPL. Establishing a wi-fi connection on my laptop fixed the problem.

[mgold]

The first time you use these tools, they download the standard library and any other libraries you need. This requires an internet connection. I was able to run elm-make without a connection but with the libraries already downloaded.

The REPL and reactor will download to the current directory, and this will cause a few seconds of delay (or this error if you're not connected). A possible improvement is to have a default, standard location for these libraries where the repl can look if you run it where there aren't libraries already.

[rtfeldman]

@mgold I just tried elm-make offline with everything already downloaded and had no luck (see elm-lang/elm-make#34) - how recently have you been able to do that successfully?

[mgold]

I checked before posting the comment. I just tried it again and it still works, using latest versions of everything.

$ mkdir tmp
$ cd tmp
$ echo "x = 5" > test.elm
$ elm make test.elm 
Some new packages are needed. Here is the upgrade plan.

  Install:
    elm-lang/core 2.1.0

Do you approve of this plan? (y/n) y
Downloading elm-lang/core
Packages configured successfully!
Success! Compiled 32 modules.                                       
Successfully generated elm.js
$ rm -r elm-stuff/build-artifacts/
$ echo "turning off wi-fi now"
turning off wi-fi now
$ elm make test.elm 
Success! Compiled 32 modules.                                       
Successfully generated elm.js

Obviously if you don't have the core libraries installed it's going to try to download them. But I haven't observed the compiler making a network request when it was unnecessary for it to do so.

[rtfeldman]

Hmmm, now I can't reproduce anymore. Not sure what the difference was, since I had definitely successfully built end-to-end on the project where I was having that problem, so I know everything was downloaded...at any rate, going to close elm-lang/elm-make#34 until I can actually reproduce it.

[evancz]

I'm gonna say we should follow along at elm-lang/elm-repl#54 which is reporting the same thing.

The root is that you need to get packages off the internet to use them. It may be possible to put them in a central place (perhaps only for elm-lang/core) so that this only needs to happen once per user instead of once per project. Not sure if that's actually a good idea though.

[vladanghene]

I've also experienced this myself at elm-lang/elm-make#156 (comment) but instead of port 80 it's 443. when I run commands with sudo it works.