David Laight wrote:
> OTOH in some cases the METALOG is written with 'echo xxx >>METALOG'
> At least some shells treat this as open, 'seek to eof' - so
> concurrent opens can lead to processes overwriting from the same
> point!

this is it...  when the zoneinfo files are installed, "find ... | sed ...
>>METALOG" updated the METALOG.  The two finds for the zoneinfo files get in
each others way AND they also interfere with the next target(s).

I believe this could also be a problem if the host runs NetBSD?
There are non-xinstall METALOG updates in etc/Makefile,
gnu/usr.bin/texinfo/install-info/Makefile, distrib/sets/Makefile,
share/man/Makefile and share/zoneinfo/Makefile.  Only the zoneinfo one
writes multiple lines.

    christian