Created attachment 17294 [details] [review]
We've receive a bug report about build failure of fontconfig during parallel build:
To explain the problem let me first show you fc-case/Makefile.am sniplet:
$(TARG): $(STMPL) fc-case$(EXEEXT) $(SCASEFOLDING)
rm -f $(TARG)
./fc-case$(EXEEXT) $(SCASEFOLDING) < $(STMPL) > $(TARG)
ALIAS_FILES = fcalias.h fcaliastail.h
BUILT_SOURCES = $(ALIAS_FILES) $(TARG)
In some cases (when touch works slower then other things) rebuilt of fccase.h
($(TARG) in BUILT_SOURCES) starts rebuild of fc-case earlier then touch
finishes and thus the error. This bug is reproducible with make -j N where N
>= 3 (as fccase.h is third in BUILT_SOURCES). To reproduce it even better just
add 'sleep 2' before touch $(ALIAS_FILES) and call make -j3 in fc-case
directory. Suggested patch to fix the issue is in attachment.
Applied in 0e21b5a4d5609a5dd0f332b412d878b6f1037d29, thanks!