Pre release sanity checking

While many of us work off git branches, a release needs to package Links and examples in such a way that they work for users who simply run "opam install links". As a result, we need to be careful to check that a release works before submitting it to OPAM.

Firstly, prepare the release according to https://github.com/links-lang/links/wiki/Release-checklist, but do not run opam publish.

Next, ensure all of the unit tests work by running "./run-tests".

Next, preferably on a clean OCaml environment, run (from the base Links source directory):

opam pin add links.opam .

This will pin the Links install to the current directory, and attempt to install it. First thing to check is that this succeeds.

Next, check that the Links REPL works by typing "linx", and evaluating a simple expression (for example, 2+2).

Next, you need to check the examples work. To do this (assuming a switch of 4.08.1 -- change this to the switch you're on), firstly navigate to your home directory then type:

cd .opam/4.08.1/share/links
linx -m --path=examples:examples/games:examples/dictionary examples/webserver/examples-nodb.links

If .opam/4.08.1/share/links does not exist, you may have to use .opam/default/share/links instead. This happens if the OCaml version you are using is the same as the one shipping with your OCaml distribution by default.

Navigate to "http://localhost:8080" and ensure that all of the non-DB examples work.

Finally, install the database and ensure that

linx -m --path=examples:examples/games:examples/dictionary examples/webserver/examples.links

runs correctly, including all of the database examples.

Note that the command above assumes that you have adapted the default configuration file used by linx to reflect your database configuration. To determine the path to this config file, you may run linx and obtain the value of the config setting from running @settings;. For example, this may be /home/the_user/.opam/4.08.1/etc/links/config