Re: build dependencies vs tools

[Jonathan Perkin <jperkin%joyent.com@localhost>]

* On 2017-09-13 at 15:46 BST, J. Lewis Muir wrote:

> On 09/11, Jonathan Perkin wrote:
> > * On 2017-09-11 at 15:47 BST, Jan Danielsson wrote:
> > 
> > > Looking at some dependencies on pkgsrc.se and a thought occurred:
> > > What's the difference between "build dependencies" and "USE_TOOLS"?
> > 
> > The main difference is that a tool can come from the operating system.
> > 
> > If an operating system comes with bison and you request bison via
> > USE_TOOLS then, as long as the OS version works fine, it will be used
> > for the build.  If you add bison as a BUILD_DEPENDS, then regardless
> > of whether the OS provides it, the pkgsrc bison package will be pulled
> > in.
> 
> What if bison had built-in support (i.e., had a builtin.mk file) and
> the OS had a bison version that satisfied the built-in requirement, and
> PREFER_NATIVE was set to yes, then a BUILD_DEPENDS of bison would use
> the bison from the OS, right?

No.  builtin.mk and PREFER_* are buildlink concepts for headers and
libraries.  The tools infrastructure does something similar but in a
different way for programs.  BUILD_DEPENDS and other *DEPENDS have no
such logic, they just add dependencies on pkgsrc packages.

-- 
Jonathan Perkin  -  Joyent, Inc.  -  www.joyent.com