Re: [PATCH 1/4] configure: Use discovered make for in-source build

[Roman Bolshakov <r.bolshakov@yadro.com>]

On Mon, Aug 24, 2020 at 09:37:07AM -0500, Eric Blake wrote:
> On 8/22/20 4:21 PM, Roman Bolshakov wrote:
> > @@ -38,6 +38,8 @@ then
> >   # This file is auto-generated by configure to support in-source tree
> >   # 'make' command invocation
> > +include build/config-host.mak
> 
> Should this use '-include' (also spelled 'sinclude'), to avoid halting the
> build if build/config-host.mak doesn't exist for whatever reason?
> 

Sure I can do (and thanks for the noticed typos) but I tested that if
the build is interrupted too early (before Makefile is symlinked to
build directory but after GNUmakefile is created) it would fail even if
-include is used:

$ make
changing dir to build for /Library/Developer/CommandLineTools/usr/bin/make ""...
make[1]: Makefile: No such file or directory
make[1]: *** No rule to make target `Makefile'.  Stop.
changing dir to build for /Library/Developer/CommandLineTools/usr/bin/make ""...
make[1]: Makefile: No such file or directory
make[1]: *** No rule to make target `Makefile'.  Stop.
make: *** [all] Error 2

I'm also curious why the switch happens twice... According to the debug
trace, it tries to remake build/config-host.mak using the implicit force
rule:

GNUmakefile:12: update target 'build/config-host.mak' due to: force

Then there should be an explicit empty rule for build/config-host.mak. I
will send a fix for that in v2. Then it would fail like this:

$ make
changing dir to build for /Library/Developer/CommandLineTools/usr/bin/make ""...
make[1]: Makefile: No such file or directory
make[1]: *** No rule to make target `Makefile'.  Stop.
make: *** [all] Error 2

Regards,
Roman

> > +
> >   ifeq ($(MAKECMDGOALS),)
> >   recurse: all
> >   endif
> > 
>