[tlbuild] Problems with parallel make

[Ken Brown]

On 2/13/2023 8:25 AM, Ken Brown wrote:
> On 2/12/2023 6:48 PM, Bruno Haible wrote:
>> Karl Berry wrote:
>>>      1. 'make -j13 world' hangs during the 'make install-strip' step, 
>>> with
>>>      several 'make' instances still running.
>>>
>>> What are they doing? Can you tell from the processes that are running
>>> when it hangs?
>>>
>>> I can't think of what would be different here than in previous years.
>>
>> Are you using the same version of 'make' as last year?
> 
> No, I'm using 4.4, and last year I used 4.3.
> 
>> At least in recent GNU make versions, there are problems with parallelism
>> on Cygwin. Reported at
>> https://lists.gnu.org/archive/html/bug-make/2023-01/msg00134.html .
>> I don't know about older versions of GNU make, though.
> 
> Thanks for the pointer.  I'll see if going back to 4.3 fixes the problem.

Problem solved: It turns out that GNU make, starting with 4.4, uses a 
FIFO instead of a pipe for its jobserver.  You can make it use a pipe by 
adding the flag '--jobserver-style=pipe', and this fixes both problems I 
reported.

There may be a bug in Cygwin's FIFO implementation underlying this, but 
I'm happy with the solution for now.

Thanks again, Bruno.

Ken