Re: Building zsh should work with "make -j2"

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

On Jan 13, 12:58am, Vincent Lefevre wrote:
}
} When building zsh with make -j2, in fact
} 
} A dependency bug in the Makefile?

Yes, but it's a really insidious one -- it's an implicit dependency on a
sequential build rather than a true file-to-file dependency that can be
expressed in make syntax.

I've tried several different ways to introduce dummy build targets to
force the one portion of the build that is required to be sequetial to
really be sequential, and failed every time.  The problem is related
to the way that zsh uses recursive invocations of make with makefiles
that are (re)compiled as part of the outer invocation; it appears to be
truly impossible to create a description of this in make syntax because
the necessary parts of the syntax can't even exist until the outer make
has already decided that it's OK to parallelize the recurive make.

That's not the whole story, but it's a large subset of it ...