Comment 20 for bug 987502

Hi Andrew.

Generally, both versions of the library are needed if one needs multi architecture building option (e.g. x86_64 native build and i386 backsupport (cross)build for 32-bit installations).

I am building my i386 and x86_64 application on Ubuntu 12.04.3 LTS using -m32 and -m64 gcc options.
But running only 64-bit version of the application locally for the matter.

To accomplish this I have done:

Firstly installed libxml2-dev (x86_64)
  sudo apt-get install libxml2-dev

Secondly, move problematic xml2-config
  sudo mv /usr/bin/xml2-config /usr/bin/xml2-config.x86_64

Then install libxml2-dev:i386
  sudo apt-get install libxml2-dev:i386

Rename xml2-config for i386
  sudo mv /usr/bin/xml2-config /usr/bin/xml2-config.i386

Restore x86_64 xml2-config
  sudo cp /usr/bin/xml2-config.x86_64 /usr/bin/xml2-config

Finally, had to call ldconfig to refresh the library paths and gcc builds my application with -m32 and excplicit -m64 (although not needed).

ldconfig reports:
$ ldconfig -p | grep xml2
 libxml2.so.2 (libc6,x86-64) => /usr/lib/x86_64-linux-gnu/libxml2.so.2
 libxml2.so.2 (libc6) => /usr/lib/i386-linux-gnu/libxml2.so.2
 libxml2.so (libc6,x86-64) => /usr/lib/x86_64-linux-gnu/libxml2.so