Experimental Physics and
Industrial Control System

Unfortunately, the build system ignores errors from not only g++ runs for depencency generation (those with -MM -MF), but ALL of them, including .cc to .o compilation (those with "-c").

It is visible in my build logs excerpts
(https://epics.anl.gov/tech-talk/2023/msg00595.php): the last command, before freeList.html, is *compilation* of epicsTempFile.cpp.  But instead of immediately stopping, the build process continues and stops a bit later because of absent epicsTempFile.o, which should have been made by g++.

# This is a Makefile fragment, see src/libCom/Makefile.

# Extra rule since asLib_lex.c is included by asLib.c
asLib$(DEP): asLib_lex.c
asLib.c: asLib_lex.c

# Ensure that lexer and parser are built before they are needed
asLib.c: $(EPICS_BASE_HOST_BIN)/antelope$(HOSTEXE)
asLib_lex.c: $(EPICS_BASE_HOST_BIN)/e_flex$(HOSTEXE)
asLib_lex.c: $(INSTALL_INCLUDE)/flex.skel.static

Is there any document describing how EPICS build system is configured to ignore *some* errors (curiously, without a use of ".IGNORE:", "--ignore" or "-" before commands)?

P.S. I'm trying to investigate this problem not because of "missing g++" (which is obviously a non-issue), but to understand how the EPICS build system works.  Which, in turn, is needed to solve another class of problems: when something goes wrong during build, e.g. "genApps" SIGSEGVs on some architectures (due to a buggy gddUtils.h), the error isn't shown "as is" immediately but the build process continues and only the "induced" error due to a missing file is shown later.

-- 
Complexity comes for free, Simplicity you have to work for.