Re: Sporadic GNU make jobserver unavailable

On 2025-12-05 02:18, Dimitry Andric via Cygwin wrote:
> We're using Cygwin make to build several projects in parallel mode, e.g.
> with -j 4 or sometimes higher settings, depending on the core count of
> the machine.
> 
> Sporadically, and then I'm talking about "once a week" or so, random
> jobs will fail with a non-repeatable error, and in _every_ case these
> failures are preceded by a warning from make:
> 
>    make[4]: warning: jobserver unavailable: using -j1.  Add '+' to parent make rule.
> 
> Obviously the "Add '+' to parent rule" is nonsensical, since simply
> running exactly the same job again almost always works fine. But there
> is something flaky about make's jobserver under Windows.
> 
> FWIW one machine I just observed this on has the make-4.4.1-2 package,
> which should use the "pipe" jobserver, if I interpret
> https://cygwin.com/pipermail/cygwin-announce/2023-March/010972.html
> correctly.
> 
> Does anybody know a way to further debug this issue? It must be some
> rare race condition...

https://stackoverflow.com/questions/60702726/warning-jobserver-unavailable-using-j1-add-to-parent-make-rule

-- 
Take care. Thanks, Brian Inglis              Calgary, Alberta, Canada

La perfection est atteinte                   Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter  not when there is no more to add
mais lorsqu'il n'y a plus rien à retrancher  but when there is no more to cut
                                 -- Antoine de Saint-Exupéry

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