--tag=LD added r23745 prevents successful compilation of GDAL trunk in OSX 10.6
The addition of --tag=LD in r23745 prevents GDAL trunk from compiling to completion. If --tag=LD is removed, GDAL trunk compiles successfully.
In the compile output, libtool outputs the following
libtool: link: ignoring unknown tag LD
The above message is also present in the output on Linux 64-bit but Linux compiles successfully with or without --tag=LD