Change install-racket.sh to:
- Use a RACKET_DIR env var saying where to install Racket. For backwards
compatibility, if undefined this defaults to /usr/racket.
- Don't use sudo unless installing to /usr*.
- Download nightly snapshot builds from Northwestern not Utah.
See https://github.com/travis-ci/travis-ci/issues/3012
- Fix the here string (which was slightly broken all along, although in
a way that had been harmless).
Change the example .travis.yml to:
- Split env into global and matrix sections.
- Specify RACKET_DIR as a global var.
- Specify the RACKET_VERSIONs as matrix vars.
- Set PATH from RACKET_DIR (because install-racket.sh can't do this --
it can't change the env for the .travis.yml).
Although that's the default for release builds, the nightly builds
default to e.g. /usr/racket-5.90.0.9. Although that default makes sense
where people are doing side-by-side installs, we're doing an install on
a throw-away Travis VM. More basically, we need the build scripts to
find stuff consistently in /usr/racket regardless of whether this is a
release or HEAD.
This uses a nightly build installer.
As the comments in install-racket.sh state, this has the weakness of
hardcoding a version like 5.90.0.9 because AFIK there is no abstract URL
meaning "whatever the latest version is".
