test: Fix caching issues (#111)

Cecca commented 9 years ago

This commit deals with the problems of caching LilyPond versions between Travis-CI builds reported in #111. Specifically, it turned out that there is not a separate cache per build-matrix entry (since LilyPond is not a supported language), but only a dedicated cache per branch.

The issue was then that only one version of LilyPond was actually used to run the tests, since the installation path was identical for all versions.

The solution introduced in this commit is to have an explicit cache management mechanism:

Each LilyPond version is installed in its own folder under the $HOME/.lilypond cache directory, for instance
```
$HOME/.lilypond/linux-64/2.18.2-1
```
Every time a cached LilyPond version is used, the timestamp is written to a file in the cache, for later retrieval
After all the tests have been run, the cache is cleaned: LilyPond versions that have not been used for more than one day (this is configurable) are removed from the cache. Note that since this cleanup phase is run after the tests have been run, all the LilyPond versions that have actually been used in the last test run are kept in the cache

Cecca commented 9 years ago

The errors reported by Travis are not related to the changes introduced in this PR, but to an issue with the Arnold font on LilyPond 2.19.17

uliska commented 9 years ago

Thank you for picking up this issue!

The Arnold font is not yet part of the distribution from fonts.openlilylib.org. So the fail doesn't indicate anything (simply to confirm Matteo's statement).

I simply skimmed the code (can't do more, as I'm on a Schubert-only weekend) and looked at the build-test log. So I think this can be merged.

openlilylib / snippets

test: Fix caching issues (#111) #117