7+ days of dogfood

[Anton Shterenlikht]

	From sgk at troutmask.apl.washington.edu Wed Feb 13 03:40:53 2013

	On Wed, Feb 13, 2013 at 02:15:08AM +0000, b.f. wrote:
	> On 2/13/13, Steve Kargl <sgk at troutmask.apl.washington.edu> wrote:
	> > On Wed, Feb 13, 2013 at 12:18:29AM +0000, b.f. wrote:
	> >> ># cat /etc/make.conf|grep FFLAGS
	> >> >FFLAGS = -O2 -pipe -march=native -mtune=native
	> >>
	> >> Please do _not_ assign flags unconditionally in make.conf.
	> >
	> > FFLAGS is for compiling Fortran.  I'm one of the people who
	> > has spent years working/patching gfortran.  I think I might
	> > have a better understanding of what options to use with
	> > gfortran than most people.
	> >
	> 
	> I know you have, but you are giving advice that is liable to be abused
	> by those who are less experienced.  The flags you are adding are not
	> the problem -- it's the way that you are adding them -- specifically,
	> the assignment in the first line of your snippet, if it's applied
	> unconditionally.  You should either be appending all of them, or
	> assigning them conditionally, so that they are sure to be assigned
	> only once, or -- preferably -- using another makefile that can't be
	> re-read multiple times during a build (ports/Mk/bsd.port.mk
	> automatically includes several makefiles that can be used for this
	> purpose, if you are building a port). You have been lucky not to trip
	> over this: every couple of months for the last several years I have
	> had to debug errors reported by users that arise from this problem. It
	> is more common with CFLAGS and CXXFLAGS but it can happen with FFLAGS,
	> too.

	Try 'find /usr/ports -name Makefile -maxdepth 3 | xargs grep FFLAGS'
	Then go read about the options chosen by the various port maintainers.
	I specifically set FFLAGS to avoid the questionable options set in 
	the ports.  If -malign-double appears in a port, it should probably
	be marked as broken.  If a port uses -fdefault-real-8, it should probably
	be marked as broken.  If a port uses -ffast-math, it may have issues that
	are extremely difficult to debug. 

(I removed freebsd-current@ and added cc to ports@)

Oi vey. I see, it is complicated.
So on the one hand some options are
risky or just wrong and must not be used.
On the other there is a large number of ports,
which might not even build if this is implemented,
and convincing upstream that they are wrong
is never easy.

Is there a middle ground?
What about appending the suggested options
to FFLAGS in ports/MK/bsd.port.mk?
Or will it make debugging ports with "questionable"
options even harder?

Anton