[Scons-users] Default() and Ignore() - seem a little awkward

[Mats Wichmann]

On 1/5/19 9:13 AM, Gary Oberbrunner wrote:
> Some people look at the COMMAND_LINE_TARGETS variable (or some other
> command line way) to decide whether to call env.Program() at all --
> especially in larger builds, that can reduce noop build time because those
> targets and their dependencies never even get scanned. But in your case,
> Mats, I think Default(Alias('DefaultBuild')) and then adding to that alias
> is the way to go. If you really want to get what SCons does by default
> (build all targets under '.') just call "scons .".

I'll be trying this, yes - thanks. There's a slight complication in this
project (of course) but I should be able to work around that.


> 
> As for your note that a Default list of None is "not legal" well, not
> exactly -- but it does mean nothing will be built by default (without some
> target specified on the cmd line), which is odd at best. Default() is
> global - it just replaces '.' as what gets built if the user doesn't
> specify any command line targets.

there's an env.Default too.. is that in fact not environment-specific
and actually global?  If so, that would explain what I was seeing.