That hangs forever.  I cloned this repo and ran `rake build`.  This is where it hangs:

```
...
/usr/bin/nm   ./.libs/libzkst.a ./.libs/libhashtable.a | sed -n -e 's/^.*[ 	]\([BCDEGRST][BCDEGRST]*\)[ 	][ 	]*_\([_A-Za-z][_A-Za-z0-9]*\)$/\1 _\2 \2/p' | /usr/bin/sed 's/.* //' | sort | uniq > .libs/libzookeeper_st.exp
grep -E -e "(zoo_|zookeeper_|zhandle|Z|format_log_message|log_message|logLevel|deallocate_|zerror|is_unrecoverable)" ".libs/libzookeeper_st.exp" > ".libs/libzookeeper_st.expT"
mv -f ".libs/libzookeeper_st.expT" ".libs/libzookeeper_st.exp"
rm -fr .libs/libzookeeper_st.lax
mkdir .libs/libzookeeper_st.lax
rm -fr .libs/libzookeeper_st.lax/libzkst.a
mkdir .libs/libzookeeper_st.lax/libzkst.a
Extracting /Users/mperham/src/zookeeper/ext/zkc-3.4.5/c/./.libs/libzkst.a
```