remove build-time dependency on llvm.org

[jfirebaugh]

This host has poor reliability, and when it goes down our builds fail.

[1ec5]

Can we at least make use of Travis’ cache: option?

[jfirebaugh]

@springmeyer Do you know where in the build process the following is coming from:

$ curl -sSL "http://llvm.org/apt/llvm-snapshot.gpg.key" | sudo -E apt-key add -
curl: (56) Recv failure: Connection reset by peer
gpg: no valid OpenPGP data found.

[springmeyer]

@jfirebaugh - I think it is coming from the whitelisted apt package we use for upgrading clang++:

mapbox-gl-native/.travis.yml

Line 19 in 1087924

sources: [ 'ubuntu-toolchain-r-test', 'llvm-toolchain-precise-3.5' ]

Can we at least make use of Travis’ cache: option?

@1ec5 - good idea. But I went to read about this and see: Note that APT caching is not available for the container-based infrastructure. at http://docs.travis-ci.com/user/caching/

[ljbade]

Just hit this too.

Why o why Travis

[mikemorris]

👍, got tripped up on this trying to get #2391 merged yesterday

[ljbade]

@1ec5 You sure it doesn't work on containers? @daniel-j-h post seems to say it does?

[1ec5]

Based on the documentation, apt caching is unavailable to us, and it's an apt package that depends on llvm.org availability. Directory-based caching may work, but it doesn't look like it'll solve this particular problem.

[ljbade]

@1ec5 I see now directory caching != apt caching

[daniel-j-h]

You could set up a local mirror or make a snapshot of the packages (e.g. check out aptly), and cache its directory. Not sure if worth the effort. You also have to think about cache invalidation.

[jfirebaugh]

There doesn't seem to be any reasonable way to do this.