libprelude started failing to cross build again. This time around it is
caused by PAC/BTI as that's adding architecture specific compiler flags.
Confusion of compiler flags earlier was harmless and now causes a build
failure. I'm attaching a patch for your convenience.

Helmut

Dear submitter,

as the package libprelude has just been removed from the Debian archive
unstable we hereby close the associated bug reports.  We are sorry
that we couldn't deal with your issue properly.

For details on the removal, please see https://bugs.debian.org/1081473

The version of this package that was in Debian prior to this removal
can still be found using https://snapshot.debian.org/.

Please note that the changes have been done on the master archive and
will not propagate to any mirrors until the next dinstall run at the
earliest.

This message was generated automatically; if you believe that there is
a problem with it please contact the archive administrators by mailing
ftpmaster@ftp-master.debian.org.

Debian distribution maintenance software
pp.
Thorsten Alteholz (the ftpmaster behind the curtain)