When the build service fails

[Maxim Kharchenko]

Dear group members,

The easiest way to take Erlang on Xen for a spin is to use a rebar plugin called
ling_builder (https://github.com/maximk/ling_builder). The plugin adds a few
subcommands to rebar that automate the process of sending beam files to the
build service and fetching the Xen image.

Sometimes the build service does fail. Such failure is a manifestation that your
code touched a dark corner of Erlang not properly addressed by LING VM or the
build system. We strive to correct such failures within hours.

A recent failure of the build service taught us that is_function(F, A) guard BIF
should be prepared to deal with situation when A is not an integer constant. Such
situation never occured in ~5000 beam files (~5.5mln instructions) we use for
validation of LING VM instruction set. We had to add yet another beam file.

It would be great if you share thoughts and suggestions about the build service.
For example, we plan to add an Amazon AMI as a target. Let us know if it makes
a difference for you and we will bump up the priority of this.

Best regards,
Maxim