Without the change there is no giarantee that facebook-marshal.h gets built before it's dependencies. On make-4.4--shuffle is able to catch missing dependency as:
$ make --shuffle
CC facebook_la-facebook-mqtt.lo
facebook-mqtt.c:23:10: fatal error: facebook-marshal.h: No such file or directory
23 | #include "facebook-marshal.h"
| ^~~~~~~~~~~~~~~~~~~~
Automake's BUILT_SOURCES builds all sources before first object file. The change pulls it there.
Before the change 1-2 builds triggered make --shuffle failure. After the change 20 sequential rebuilds succeeded without failures.
Without the change there is no giarantee that facebook-marshal.h gets built before it's dependencies. On
make-4.4
--shuffle
is able to catch missing dependency as:Automake's BUILT_SOURCES builds all sources before first object file. The change pulls it there.
Before the change 1-2 builds triggered
make --shuffle
failure. After the change 20 sequential rebuilds succeeded without failures.