It rebuilds the dynamic library in lib, then in gsi you get

DYLD_LIBRARY_PATH=../lib:/sw/lib:/pkgs/gcc-4.1.0/lib:/usr/local/ Gambit-C/lib/:/sw/lib ../gsc/gsc -:=".." -f -c -check _gsi.scm make[1]: *** [_gsi.c] Illegal instruction

The problem is, you're trying to execute the old gsc, which depends on the old libgambc.dylib, with the recently-built libgambc.dylib.

Perhaps we just need a "Don't do that" message in the documentation.

Brad