Travis cache

[expobrain]

Added cache for Travis and Swift assets

[asottile]

oh man I was hoping there was a way to speed this up.

if this works you're a genius thank you so much 🙏

[asottile]

🤔

WARNING: timestamping does nothing in combination with -O. See the manual
for details.

[expobrain]

Argh, missed that! Let me check for alternatives

[asottile]

I'm surprised (?) that this directory doesn't need to be created first? should there be a mkdir -p "$HOME/.swift" above this? (note that I also use this script to test locally :D)

[asottile]

another idea if wget doesn't pan out (though it seems from travis-ci that this works!) would be to checksum test the file and retrieve if incorrect (missing)

[expobrain]

pushd:

now that you mention that I'm surprise as well. My untested theory is that Travis creates the directory in cache->directories ahead of time so pushd is not failing.

[expobrain]

wget:

you mean storing the hardcoded checksum for the Swift tarballs in the script and check them at runtime? Can do it, probably a little paranoid-ish but still a good point

[asottile]

I meant more if we couldn't find a solution that worked with wget :)

let's add the mkdir -p so I can keep using this script locally and then I'll merge this!

[asottile]

Thanks again!