Normally, that is not an error per se; it is a warning that the first file it found that matches the -lPI-Http argument to the compiler/linker is not valid. The error occurs when no other library can be found with the right content.
So, you need to look to see whether /dvlpmnt/libPI-Http.a is a library of 32-bit object files or of 64-bit object files - it will likely be 64-bit if you are compiling with the -m32 option. Then you need to establish whether there is an alternative libPI-Http.a or libPI-Http.so file somewhere else that is 32-bit. If so, ensure that the directory that contains it is listed in a -L/some/where argument to the linker. If not, then you will need to obtain or build a 32-bit version of the library from somewhere.
To establish what is in that library, you may need to do:
mkdir junk
cd junk
ar x /dvlpmnt/libPI-Http.a
file *.o
cd ..
rm -fr junk
The 'file' step tells you what type of object files are in the archive. The rest just makes sure you don't make a mess that can't be easily cleaned up.