Re: Prepending '+' to the recipe line when linking with GCC's -flto=jobserver

[Karl Berry]

Hi - sorry for the absurdly delayed reply. Almost a year ago, you wrote
to this list about prepending a + to link lines:

    Date: Tue, 18 Feb 2020 16:47:05 +0100
    From: "R. Diez" <rdiezmail-temp2@yahoo.de>
    To: automake@gnu.org
    Subject: Prepending '+' to the recipe line when linking with GCC's
     -flto=jobserver

    I am developing firmware similar to this one:
    https://github.com/rdiez/JtagDue
    ...
    
    https://lists.gnu.org/archive/html/automake/2020-02/msg00012.html

I admit I am not immediately sure how to approach this.  Precedents are
not coming to mind. Some sort of flag in Makefile.am that Automake
recognizes and then adds the +, I guess. Jim, wdyt?

At any rate, it would be extremely helpful to have a minimal-as-possible
runnable (automake-able) example showing the case where the + needs to
be prepended. rdiez, can you create such a mini-project? If you have
time to do that, please send it to bug-automake@gnu.org, since that's
more trackable than this list.

Thanks,
Karl