Library libtdbc used in restore_ports script is unsigned

[Joshua Root]

> I recently upgraded from macOS 13.x to macOS 14.3.1 Sonoma and started running the MacPorts Migration process. I got interrupted and did the minor macOS update to macOS 14.4 and tried to run the “restore_ports.tcl” script, which worked for a while but then threw an error about the libtdbc library being unsigned. I don’t know if this is something that changed recently. What is the recommended procedure for fixing this? Uninstall all the ports and reinstall them?
>
> This is the full error:
> dlopen(/opt/local/lib/tdbc1.1.7/libtdbc1.1.7.dylib, 0x0006): tried: '/opt/local/lib/tdbc1.1.7/libtdbc1.1.7.dylib' (code signature in <3CE89C0F-A387-3934-8B3D-5834290B7BD3> '/opt/local/lib/tdbc1.1.7/libtdbc1.1.7.dylib' not valid for use in process: mapped file has no cdhash, completely unsigned? Code has to be at least ad-hoc signed.), '/System/Volumes/Preboot/Cryptexes/OS/opt/local/lib/tdbc1.1.7/libtdbc1.1.7.dylib' (no such file), '/opt/local/lib/tdbc1.1.7/libtdbc1.1.7.dylib' (code signature in <3CE89C0F-A387-3934-8B3D-5834290B7BD3> '/opt/local/lib/tdbc1.1.7/libtdbc1.1.7.dylib' not valid for use in process: mapped file has no cdhash, completely unsigned? Code has to be at least ad-hoc signed.)
>      while executing
> "load /opt/local/lib/tdbc1.1.7/libtdbc1.1.7.dylib Tdbc"
>      ("package ifneeded tdbc 1.1.7" script)
>      invoked from within
> "package require tdbc"
>      (file "/opt/local/lib/tcl8/8.6/tdbc/sqlite3-1.1.7.tm" line 13)
>      invoked from within

This is likely an unfortunate interaction with a feature of tclsh and a 
feature of macOS. Tcl will look for packages in the same prefix as the 
interpreter that is running the script, and in this case, the tclsh 
shipped with MacPorts base finds a tdbc library installed by a port. The 
former is signed and the latter is not, and macOS doesn't allow signed 
executables to load unsigned libraries.

The most straightforward workaround is to use a different path for the 
interpreter. /opt/local/bin/port-tclsh is a symlink to the actual 
tclsh8.6 in a subdirectory, so running the script like this should work:

sudo `readlink /opt/local/bin/port-tclsh` ./restore_ports.tcl

Hopefully we can ship automatic migration in MacPorts base soon and 
retire restore_ports.tcl.

- Josh