Re: How does $bob_packages work?

* On 2026-05-18 at 15:35 BST, Benny Siegert wrote:

>I updated bob to 0.99.5, and I am trying to convert my existing config.
>
>I noticed that the new default config file, created by "bob init", 
>contains a reference to a "$bob_packages" variable, but I cannot seem 
>to find documentation about it. Am I supposed to set it?

There are a list of standard environment variables, set using the 
bob_* prefix, that are used by the internal build scripts but also 
exported to the environment used in actions and hooks:

   https://docs.rs/bob/latest/bob/action/index.html#environment-variables

Many of them are set directly from equivalent pkgsrc variables, and 
computed once at the start, so for example bob_packages is set to the 
value retrieved by:

   $ bmake show-var VARNAME=PACKAGES

You don't need to set any of them, they are calculated at the start, and 
then cached in the database for that build run.  The general principle 
is that you don't need to set anything - configure everything in mk.conf 
as you normally would for any other build environment, and bob will 
retrieve anything it needs directly.  The only reason they are exposed 
is because sometimes it's useful to perform some additional sandbox 
setup that requires them, like the $bob_prefix used by dev sandboxes.

A natural follow-up question would be "why not just use $PACKAGES rather 
than $bob_packages" and the answer is because setting them directly in 
the environment like that would wipe out any ?= settings.  The separate 
bob_* namespace keeps everything clean.

Hope that helps.  I know the docs aren't ideal right now, I do plan to 
improve them once I've finished with the code.

-- 
Jonathan Perkin                    pkgsrc.smartos.org
Open Source Complete Cloud   www.tritondatacenter.com