Why is LD_LIBRARY_PATH unset in FC6 and not in FC5

[Phil Meyer]

Pelle Svensson wrote:
> Hi,
>
> Why is LD_LIBRARY_PATH not exported in following test on FC6.
>
> Put Makefile, SubMakefile and Subscript in a directory and issue make.
>
> Result if run as user:
> []$ make
> ================
> In Makefile: LD_LIBRARY_PATH=/home/testing and TEST_PATH=/home/testing
> make[1]: Entering directory `/home/pelle/diverse/make-fc6'
> In SubMakefile: LD_LIBRARY_PATH= and TEST_PATH=/home/testing
> make[1]: Leaving directory `/home/pelle/diverse/make-fc6'
> In SubScript: LD_LIBRARY_PATH=/home/testing and TEST_PATH=/home/testing
>
>
> Result if run as root:
> []$ sudo make
> ================
> In Makefile: LD_LIBRARY_PATH=/home/testing and TEST_PATH=/home/testing
> make[1]: Entering directory `/home/pelle/diverse/make-fc6'
> In SubMakefile: LD_LIBRARY_PATH=/home/testing and TEST_PATH=/home/testing
> make[1]: Leaving directory `/home/pelle/diverse/make-fc6'
> In SubScript: LD_LIBRARY_PATH=/home/testing and TEST_PATH=/home/testing
>
>
> On FC5 when running as user SubMakefile will have 
> 'LD_LIBRARY_PATH=/home/testing'
>
> /Pelle
>
> _________________________________________________________________
> Spela roliga Worms'07 i mobilen 
> http://msn.cellus.se/?page=game_order&itemId=878908

I am no expert in compilers, but this issue has existed sin we were 
doing gcc on Solaris 2.1 (1992).  Someone with better knowledge feel 
free to respond, but these are my observations:

root has special precautions about prepended library paths.  That is a 
common trick of old security hackers.

In modern times. LD_LIBRARY_PATH simply should not be used any where.

When building an application you can set LD_RUN_PATH and that will embed 
the run path into the binary.

For applications that might move locations, there has been a method 
provided for years, by placing a simple text file with a run path in 
/etc/ld.so.conf.d the loader linker will use it as if LD_LIBRARY_PATH 
had been set.

This makes for an easily relocatable rpm, because the rpm can drop a 
text file in there that points to wherever the rpm has been located.

In your example above, simply change LD_LIBRARY_PATH to LD_RUN_PATH and 
you will get what you want, AND users will not need to set LD_LIBRARY_PATH.

Some discussion here:

http://osr507doc.sco.com/en/tools/ccs_linkedit_dynamic_dirsearch.html

LD_RUN_PATH seems to be absent here:

http://gcc.gnu.org/onlinedocs/gcc-4.2.0/gcc/Environment-Variables.html#Environment-Variables

So maybe I am just getting old, but I am sure that the principle is 
good, even if my failing memory is not. :)