problems compiling amarok git

[Aran Cox]

I installed taglib-1.6 and taglib-extras-1.0.0 by modifying spec files
from previous versions and installing the rpm.  I am fairly certain
there are no leftover other versions of taglib hiding on my system,
but when I compile amarok from git:

Linking CXX shared library ../lib/libamaroklib.so
CMakeFiles/amaroklib.dir/__/shared/taglib_filetype_resolvers/asffiletyperesolver.o:
In function `ASFFileTypeResolver::createFile(char const*, bool,
TagLib::AudioProperties::ReadStyle) const':
/home/acox/src/amarok/shared/taglib_filetype_resolvers/asffiletyperesolver.cpp:32:
undefined reference to `CheckExtensionImpl(char const*, char const*)'
/home/acox/src/amarok/shared/taglib_filetype_resolvers/asffiletyperesolver.cpp:32:
undefined reference to `CheckExtensionImpl(char const*, char const*)'
CMakeFiles/amaroklib.dir/__/shared/taglib_filetype_resolvers/mp4filetyperesolver.o:
In function `MP4FileTypeResolver::createFile(char const*, bool,
TagLib::AudioProperties::ReadStyle) const':
/home/acox/src/amarok/shared/taglib_filetype_resolvers/mp4filetyperesolver.cpp:31:
undefined reference to `CheckExtensionImpl(char const*, char const*)'
/home/acox/src/amarok/shared/taglib_filetype_resolvers/mp4filetyperesolver.cpp:31:
undefined reference to `CheckExtensionImpl(char const*, char const*)'
/home/acox/src/amarok/shared/taglib_filetype_resolvers/mp4filetyperesolver.cpp:31:
undefined reference to `CheckExtensionImpl(char const*, char const*)'
CMakeFiles/amaroklib.dir/__/shared/taglib_filetype_resolvers/mp4filetyperesolver.o:/home/acox/src/amarok/shared/taglib_filetype_resolvers/mp4filetyperesolver.cpp:31:
more undefined references to `CheckExtensionImpl(char const*, char
const*)' follow
CMakeFiles/amaroklib.dir/__/shared/taglib_filetype_resolvers/mimefiletyperesolver.o:
In function `MimeFileTypeResolver::createFile(char const*, bool,
TagLib::AudioProperties::ReadStyle) const':
/home/acox/src/amarok/shared/taglib_filetype_resolvers/mimefiletyperesolver.cpp:76:
undefined reference to `TagLibExtras::RealMedia::File::File(char
const*, bool, TagLib::AudioProperties::ReadStyle)'
collect2: ld returned 1 exit status
make[2]: *** [lib/libamaroklib.so.1.0.0] Error 1
make[1]: *** [src/CMakeFiles/amaroklib.dir/all] Error 2
make: *** [all] Error 2

It sure seems like I've done something wrong but I'm not sure what.
The cmake output for building amarok looks like this:
-- Taglib found: -L/usr/lib -ltag
-- Performing Test TAGLIB_ASF_FOUND
-- Performing Test TAGLIB_ASF_FOUND - Success
-- Performing Test TAGLIB_MP4_FOUND
-- Performing Test TAGLIB_MP4_FOUND - Success
-- checking for module 'taglib-extras>=1.0'
--   found taglib-extras, version 1.0.0
-- Found Taglib-Extras: /usr/include/taglib-extras
-- Performing Test COMPLEX_TAGLIB_FILENAME
-- Performing Test COMPLEX_TAGLIB_FILENAME - Failed

Any suggestions?