Help with package that has a build dependency on a Linux binary

[Jason Thorpe <thorpej%me.com@localhost>]

Hey folks --

I'm working on a package update that has a dependency on a Linux x86_64 binary for which sources are not available.  I have the package building on my local NetBSD/amd64 system, with the suse_base-13.1nb15 emulation package installed.  This is only a build-time dependency.  Once built, the single package can be installed on any system (it's a u-boot package, so nothing actually runs on the system you install it on -- it's just a blob that's blasted on an SDMMC card later).

Because this tool is really only useful for this particular package, I'm loathe to make a separate package just for it (and eventually, open source replacements for this tool may work, but for the moment, they don't).

Right now, my work-in-progress just downloads the binaries from the vendor, chmod's them, and runs them from $DISTDIR, and I have:

BUILD_DEPENDS+=         suse_base>=13.1nb15:../../emulators/suse131_base

...to express the dependency on the Linux emulation package (it may work with an older one, but I haven't tried it, and nor am I likely to).

This particular u-boot package is also part of the u-boot meta package, and I guess I'd like some way to express "optionally depends on" for that.

Can someone help me out of this pickle?

-- thorpej