Specifically it is failing to fetch the patchfile patch-contrib-sb-posix-posix-tests.lisp.diff. Normally MacPorts doesn't need to fetch patchfiles because normally they're in the files directory.
This patchfile is not in the files directory because it is not referenced by the port. The reference to it was removed over a year ago. See #67912 for the previous time this issue was reported. There, the problem seemed to be caused by an outdated ports tree and was solved by updating it.
But your ports tree appears to be up to date already because your log shows sbcl 2.4.4. I don't understand how the reference to that patchfile could still be in your Portfile when the reference was removed while the port's version was 2.3.5. Have you manually modified your sbcl Portfile to reintroduce the reference to this patch? If you do not recall modifying the Portfile, maybe it would help if you attach the Portfile so that we can compare it with what's in our repository. The command port file sbcl shows you where the Portfile is.
