Selfupdate from 2.3.5 to 2.4.0 fails on Mac OS X 10.5.8 Leopard

[hotsupport]

Sample output from port -v selfupdate:

configure: === configuring in vendor/tcl/unix (/opt/local/var/macports/sources/rsync.macports.org/release/base/vendor/tcl/unix)
configure: error: no configure script found in vendor/tcl/unix
Command failed: cd /opt/local/var/macports/sources/rsync.macports.org/release/base && CC=/usr/bin/cc OBJC=/usr/bin/cc ./configure --prefix='/opt/local' --with-install-user='root' --with-install-group='admin' --with-directory-mode='0755' --enable-readline && make SELFUPDATING=1 && make install SELFUPDATING=1
Exit code: 1
Error: Error installing new MacPorts base: command execution failed
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Error: /opt/local/bin/port: port selfupdate failed: Error installing new MacPorts base: command execution failed

port command is otherwise functional (this is an old install which has worked great for years)

[mf2k (Frank Schima)]

Duplicate of #53414.