feature request: stronger LD_RUN_PATH

[Paul Jarc]

In general, it's easier to pass environment variables to a compilation
command than to pass command line arguments; some build systems don't
make it easy to specify arguments, but they generally don't clear the
environment.  Even when they do let you pass arguments, they have
different ways of doing it; environment variables are just there.  So
I like using C_INCLUDE_PATH, LIBRARY_PATH, and LD_RUN_PATH rather than
-I, -L, and -Wl,-R.

The problem is that some packages add their own -Wl,-R arguments.
With -I and -L, this isn't a problem; the environment variables are
used along with the arguments.  But -Wl,-R is used *instead of*
LD_RUN_PATH.  I'd like to have some way of expressing, via environment
variables, "add these directories to the rpath list, in addition to
any given on the command line".  I'd also like to be able to specify
the path to the dynamic linker in the environment, although since
there can be only one dynamic linker, it makes sense for the one given
on the command line to be favored.


paul