fixup! Build libtcl

Author: geofft

cpython-unix/build-cpython.sh

@@ -705,6 +705,8 @@ if [ "${PYBUILD_SHARED}" = "1" ]; then
             ${ROOT}/out/python/install/bin/python${PYTHON_MAJMIN_VERSION}
 
         # Python's build system doesn't make this file writable.
+        # TODO(geofft): @executable_path/ is a weird choice here, who is
+        # relying on it? Should probably be @loader_path.
         chmod 755 ${ROOT}/out/python/install/lib/${LIBPYTHON_SHARED_LIBRARY_BASENAME}
         install_name_tool \
             -change /install/lib/${LIBPYTHON_SHARED_LIBRARY_BASENAME} @executable_path/${LIBPYTHON_SHARED_LIBRARY_BASENAME} \
@@ -718,6 +720,14 @@ if [ "${PYBUILD_SHARED}" = "1" ]; then
             -change /tools/deps/lib/libz.1.dylib /usr/lib/libz.1.dylib \
             ${ROOT}/out/python/install/lib/${LIBPYTHON_SHARED_LIBRARY_BASENAME}
 
+        # At the moment, python3 and libpython don't have shared-library
+        # dependencies, but at some point we will want to run this for
+        # them too.
+        for module in ${ROOT}/out/python/install/lib/python*/lib-dynload/*.so; do
+            install_name_tool \
+                -rpath @loader_path/../..
+        done
+
         if [ -n "${PYTHON_BINARY_SUFFIX}" ]; then
             install_name_tool \
                 -change /install/lib/${LIBPYTHON_SHARED_LIBRARY_BASENAME} @executable_path/../lib/${LIBPYTHON_SHARED_LIBRARY_BASENAME} \