Issues w/ "relink" and cross-compilation

[Philip Prindeville]

I'm the lead developer and distro manager for astlinux.  It's an 
embedded run-from-flash distro, so everything is cross-compiled by 
necessity.

The problem is that a lot of projects that we use in turn use libtool 
(and not always terribly up-to-date versions of it), and what seems to 
happen is that the relink stage uses -L/usr/lib by default, even when 
cross-compiling.

libtool: relink: 
/home/philipp/kernel/build_i586/staging_dir/bin/i586-linux-uclibc-gcc -shared  
.libs/agent_handler.o .libs/agent_index.o .libs/agent_read_config.o 
.libs/agent_registry.o .libs/agent_sysORTable.o .libs/agent_trap.o 
.libs/kernel.o .libs/snmp_agent.o .libs/snmp_vars.o mibgroup/smux/.libs/smux.o 
mibgroup/mibII/.libs/vacm_conf.o mibgroup/snmpv3/.libs/usmConf.o 
helpers/.libs/all_helpers.o helpers/.libs/baby_steps.o 
helpers/.libs/bulk_to_next.o helpers/.libs/cache_handler.o 
helpers/.libs/debug_handler.o helpers/.libs/instance.o 
helpers/.libs/mode_end_call.o helpers/.libs/multiplexer.o helpers/.libs/null.o 
helpers/.libs/old_api.o helpers/.libs/read_only.o helpers/.libs/row_merge.o 
helpers/.libs/scalar.o helpers/.libs/scalar_group.o helpers/.libs/serialize.o 
helpers/.libs/snmp_get_statistic.o helpers/.libs/stash_cache.o 
helpers/.libs/stash_to_next.o helpers/.libs/table.o helpers/.libs/table_array.o 
helpers/.libs/table_container.o helpers/.libs/table_data.o 
helpers/.libs/table_dataset.o helpers/.libs/table_iterator.o 
helpers/.libs/table_row.o helpers/.libs/table_tdata.o helpers/.libs/watcher.o   
-L/home/philipp/kernel/build_i586/staging_dir/usr/lib -L/usr/lib -lnetsnmp 
-L/home/philipp/kernel/build_i586/staging_dir/lib -lcrypto  -march=k6-2 
-isysroot /home/philipp/kernel/build_i586/staging_dir   -Wl,-soname 
-Wl,libnetsnmpagent.so.25 -o .libs/libnetsnmpagent.so.25.0.0


note the -L/usr/lib which is dead-wrong.

There's probably a really simple trick to getting this not to happen, but it's 
not obvious to me.  Also, it would be nice if libtool figured out the need to 
do this on its own (i.e. figure out that it's cross-compiling and that -Lxxx 
for any host libraries shouldn't be included).

Can someone walk me through the workaround?

We've had this issues with libusb-1.0 and netsnmp that have stopped us from 
bumping versions... not having a solution here is a gating factor for us.

Thanks,

-Philip