pkg/59052: bootstrap: --make-jobs should be passed into mk.conf MAKE_JOBS

[campbell+netbsd%mumble.net@localhost]

>Number:         59052
>Category:       pkg
>Synopsis:       bootstrap: --make-jobs should be passed into mk.conf MAKE_JOBS
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Feb 07 12:25:01 +0000 2025
>Originator:     Taylor R Campbell
>Release:        current
>Organization:
NetBSD Bootstrap Jobs LLC
>Environment:
>Description:
Currently, if you bootstrap pkgsrc with `./bootstrap --make-jobs 4', the _bootstrap_ build will be parallelized four ways, but when you later build packages in pkgsrc with the resulting bmake, it won't be parallelized.

This is confusing, and not written down obviously: users expect that if you do `./bootstrap --make-jobs 4' then pkgsrc builds will be parallelized fourways.

There may be a good reason for it -- e.g., maybe you're building a bootstrap kit on highly parallel machine but you're going to install it on a single-core machine later -- but perhaps if so, we should have two options, one for mk.conf MAKE_JOBS and one for the bootstrap parallelism (defaults to the mk.conf MAKE_JOBS).
>How-To-Repeat:
./bootstrap --make-jobs 4
cd cat/pkg && bmake

observe no parallelism
>Fix:
Either:

(a) Set MAKE_JOBS in the resulting mk.conf when `--make-jobs N' is specified.

or

(b) 1. Set MAKE_JOBS in the resulting mk.conf when `--make-jobs N' is specified.
    2. Add another `--boot-make-jobs N' or something to override it just for the bootstrap.

or

(c) Make it clear somehow that the `--make-jobs' option does not affect future pkgsrc builds, and obvious that you need to put it in the mk.conf fragment or your mk.conf later.