Question

While trying to build the mysql2 gem with ruby 1.9.2-p320 on Fedora 16, I ran into this error,
reproducible like so:

gremlin:mysql2 $ cat conftest.c
    #include "ruby.h"

    /*top*/
    int main() {return 0;}
    int t() {
      void ((*volatile p)());
      p = (void ((*)()))rb_thread_blocking_region;
      return 0;
    }

gremlin:mysql2 $ gcc -o conftest -I/usr/local/include/ruby-1.9.1/i686-linux \
    -I/usr/local/include/ruby-1.9.1/ruby/backward 
    -I/usr/local/include/ruby-1.9.1 -I. 
    -I/usr/local/include/ruby-1.9.1/  
    -D_FILE_OFFSET_BITS=64   -O3 -ggdb -Wextra -Wno-unused-parameter 
    -Wno-parentheses -Wpointer-arith -Wwrite-strings -Wno-missing-field-initializers
    -Wno-long-long conftest.c  -L. -L/usr/local/lib -Wl,-R/usr/local/lib -L.  
    -rdynamic -Wl,-export-dynamic     -Wl,-R -Wl,/usr/local/lib -L/usr/local/lib 
    -lruby-static  -lpthread -lrt -ldl -lnss3 -lcrypt -lm   -lc

    /usr/lib/gcc/i686-redhat-linux/4.6.3/../../../libcrypt.a(md5-crypt.o): 
    In function `__md5_crypt_r':
            (.text+0x96): undefined reference to `NSSLOW_Init'

    /usr/lib/gcc/i686-redhat-linux/4.6.3/../../../libcrypt.a(md5-crypt.o): 
    In function `__md5_crypt_r':
            (.text+0xb1): undefined reference to `NSSLOWHASH_NewContext'

… and many more messages for other global functions in the nsslowhash library,
which it looks like /usr/lib/libcrypt.a expects to have available, but I don’t have
it installed, and can’t find the source for.

Actually, that’s not totally true. I found nsslowhash as part of
the Mozilla-Central build for Firefox, but when I run nm on the compiled
.a and .so files, none of them define anything that matches NSSLOW.
So where do these names come from?

Any help appreciated.

Answer 1

Problem solved by adding -lfreebl3 to the LIBS CONFIG setting.