Multiple definition of gnulib symbols

[Simon Josefsson]

I've received a report where building GNU SASL, linked to GnuTLS,  
fails because both projects use gnulib.  Errors look like:

/bin/bash ../libtool --tag=CC   --mode=link gcc  -Os -ffunction- 
sections -fdata-sections  -s -Wl,--gc-sections -static -o gsasl  
gsasl.o gsasl_cmd.o imap.o smtp.o callbacks.o ../l
ib/src/libgsasl.la ../gl/libgl.la -L/usr/lib -lreadline -lncurses -L/ 
usr/lib -lgnutls -L/usr/lib -ltasn1 -L/usr/lib -lgcrypt -L/usr/lib - 
lgpg-error -L/usr/lib -lz -L/usr/lib -lns
l -L/usr/lib -lintl -L/usr/lib -liconv -L/usr/lib -lc
mkdir .libs
gcc -Os -ffunction-sections -fdata-sections -s -Wl,--gc-sections -o  
gsasl gsasl.o gsasl_cmd.o imap.o smtp.o callbacks.o  ../lib/src/.libs/ 
libgsasl.a ../gl/.libs/libgl.a -L/usr/li
b -lreadline -lncurses /usr/lib/libgnutls.a /usr/lib/libtasn1.a /usr/ 
lib/libgcrypt.a /usr/lib/libgpg-error.a -lz -lnsl /usr/lib/libintl.a / 
usr/lib/libiconv.a -lc
/usr/lib/libgnutls.a(gc-libgcrypt.o)(.text.gc_init+0x0): In function  
`gc_init':
: multiple definition of `gc_init'
../lib/src/.libs/libgsasl.a(gc-gnulib.o)(.text.gc_init+0x0): first  
defined here
/usr/lib/gcc/i686-pc-linux-gnu/3.4.6/../../../../i686-pc-linux-gnu/ 
bin/ld: Warning: size of symbol `gc_init' changed from 7 in ../lib/ 
src/.libs/libgsasl.a(gc-gnulib.o) to 64 in .
./lib/src/.libs/libgsasl.a(gc-gnulib.o)

Yes, he's building static libraries only, and linking everything  
statically, and generally seems to have weird strange gcc flags.

My ld/ar-fu is not strong enough to know how to solve this problem.   
Is this namespace conflict a real problem in the gnulib design, and  
that the only reason we aren't seeing it more widely is that nobody  
links things statically and/or use gnulib in that many libraries  
yet?  Or is there some libtool/ld/etc setting that gnulib or my  
projects should use, to avoid causing this situation?

It seems clear that the problem is that both libgnutls and libgsasl  
contains the same gnulib symbols.

One solution might be for gnulib-tool to change the namespace of all  
gnulib functions to 'gnutls_*' and 'gsasl_*' respectively, when  
importing them into each project.  That seems somewhat ugly though.

/Simon