USE_LDCONFIG & linux ports

[John E Hein]

Careful about using USE_LDCONFIG with linux ports.

With the current ports infrastructure you may wind up running ldconfig
on the native ldconfig database (i.e., without -r /compat/linux).

As an example, try replacing INSTALLS_SHLIB=yes with USE_LDCONFIG=yes
in x11/linux-xorg-libs/Makefile.  Then run make install.  It will do
this:

.
.
===>   Running ldconfig
/sbin/ldconfig -m /compat/linux/lib
.
.

(note the lack of '-r /compat/linux')

If you try it, I recommend you do this in a chroot, just in case ;).

The root of the cause is that the old way (INSTALLS_SHLIB) uses
LDCONFIG_CMD.  The new way (USE_LDCONFIG) uses LDCONFIG.  Having
USE_LINUX_PREFIX causes bsd.port.mk to add -r /compat/linux to
LDCONFIG_CMD (and not LDCONFIG).

I don't have a patch at the moment, but I would probably start by
trying to use LDCONFIG instead of LDCONFIG_CMD in the USE_LINUX stuff
in bsd.port.mk.