If you download glibc-2.3.1-34.src.rpm, install it, change nptlarches to
"noarch", and try to do "rpmbuild --target i686 glibc.spec", at some point in
the process you get an error about the directory /lib/i686 being absent. I got
rid of it by deleting these two lines from the spec file:
Should be fixed in glibc-2.3.1-37.