svn commit: r338330 - head/lib/libmd

[Rodney W. Grimes]

> On Sun, 2018-08-26 at 10:15 -0700, Rodney W. Grimes wrote:
> > > 
> > > On Sun, 2018-08-26 at 17:05 +0000, Sean Bruno wrote:
> > > > 
> > > > Author: sbruno
> > > > Date: Sun Aug 26 17:05:43 2018
> > > > New Revision: 338330
> > > > URL: https://svnweb.freebsd.org/changeset/base/338330
> > > > 
> > > > Log:
> > > > ? r338270 had the side effect of no longer installing libmd.so
> > > > into /lib.
> > > > ? For users who have a seperate zfs mount of /usr or /usr/lib,
> > > > this will
> > > > ? cause dynamic loading failures when attempting to execute zfs
> > > > mount on
> > > > ? bootup. E.g. the system won't boot.
> > > > ??
> > > > ? Including??sets SHLIBDIR, so SHLIBDIR?= has no
> > > > ? effect.??The other lib/ Makefiles solve this problem by moving
> > > > the
> > > > ? SHLIBDIR??assignment to before .include .
> > > > ??
> > > > ? Submitted by:	jilles
> > > > ? Reviewed by:	allanjude
> > > > ? Approved by:	re (rgrimes)
> > > > ? Differential Revision:	https://reviews.freebsd.org/D1691
> > > > 0
> > > > 
> > > > Modified:
> > > > ? head/lib/libmd/Makefile
> > > > 
> > > > Modified: head/lib/libmd/Makefile
> > > > =================================================================
> > > > =============
> > > > --- head/lib/libmd/Makefile	Sun Aug 26 13:08:50 2018	
> > > > (r338329)
> > > > +++ head/lib/libmd/Makefile	Sun Aug 26 17:05:43 2018	
> > > > (r338330)
> > > > @@ -1,11 +1,12 @@
> > > > ?# $FreeBSD$
> > > > ?
> > > > +SHLIBDIR?= /lib
> > > > +
> > > > ?.include?
> > > > ?
> > > > ?PACKAGE=lib${LIB}
> > > > ?LIB=	md
> > > > ?SHLIB_MAJOR= 6
> > > > -SHLIBDIR?= /lib
> > > > ?SRCS=	md4c.c md5c.c md4hl.c md5hl.c \
> > > > ?	rmd160c.c rmd160hl.c \
> > > > ?	sha0c.c sha0hl.c sha1c.c sha1hl.c \
> > > > 
> > > I'm curious why this is the preferred solution, as opposed to just
> > > leaving the assignment where it is and changing ?= to just =.
> > I think that reason would be that one could override
> > SHLIBDIR from a higher level, if they happened to
> > need to do that.??Ie, I could build a FreeBSD release
> > that had SHLIBDIR=/usr/lib from the top level and
> > it would just work.??(This can be done if you know
> > that / and /usr/lib well be in the same file system
> > for instance.??I could also build SHLIBDIR=/lib and
> > forgo the need for /usr/lib.
> > 
> 
> Oh, hmm. I wasn't thinking of that as a knob that would be controllable
> from outside of the build system internals. IMO, that whole subject is
> a bit of a weakness of the freebsd build machinery... we don't define,
> either via documentation or (better, IMO) via consistant variable and
> target name prefixes, which things are intended to be user-settable
> controls and which are intended only for internal use.

Back in the day it most of it was defined fairly well,
but over time as the complexity grew things have become
rather muddy.

I also suspect that there is probably some breakage if you
try to do what I mention above, but those are bugs that should
be fixed.

-- 
Rod Grimes                                                 rgrimes at freebsd.org