expect: Fix install name for libexpect dylib

Closes: https://trac.macports.org/ticket/70935

devel/expect/Portfile

@@ -5,7 +5,7 @@ PortSystem 1.0
 name            expect
 conflicts       bahamut whois
 version         5.45.4
-revision        2
+revision        3
 categories      devel
 license         Tcl/Tk
 maintainers     nomaintainer
@@ -74,7 +74,13 @@ configure.args      --mandir=${prefix}/share/man \
 test.run        yes
 test.target     test
 
-post-destroot       { ln -s expect${version}/libexpect${version}.a ${destroot}${prefix}/lib/libexpect.a
+post-destroot       { 
+            ln -s expect${version}/libexpect${version}.dylib ${destroot}${prefix}/lib/libexpect.dylib
+            # Fix libexpect's install name to match its new location.
+            system "install_name_tool -id ${prefix}/lib/libexpect.dylib ${destroot}${prefix}/lib/libexpect.dylib"
+            # The expect binary has already been linked against the old install
+            # name, so we need to fix that too.
+            system "install_name_tool -change libexpect${version}.dylib ${prefix}/lib/libexpect.dylib ${destroot}${prefix}/bin/expect"
 
             file mkdir ${destroot}${prefix}/share/doc/${name}/examples
             xinstall -m 644 {*}[glob ${worksrcpath}/example/*] \