Created attachment 603542 [details]
When compiling sys-block/blktrace-1.2.0, it sometimes failed because blkiomon is regenerated in the install phase. Because CC is only overridden in the compile phase, we have a compilation error (see bad_blktrace.txt - some compilation and directories have been shortened for readability)
The issue is rbtree.o is needed by both btt/btt and blkiomon, and they are compiled in parallel, so it is possible when make -C btt is invoked, rbtree.o is not present yet, and that make process will force its recompilation, even if rbtree.o will be compiled in the meantime for blkiomon.
It is possible to address the problem by populating CC variable at install time, but a cleaner approach is to add $(PROGS) as a dependency on $(SUBDIRS).
I will propose a fix in email@example.com mailing list soon.
Created attachment 603544 [details, diff]
Created attachment 603546 [details, diff]
v2 : patch with upstream fix
Fix with signed off patch.