XMPP app fails to install

I'm unable to install the XMPP app in freedombone from the buster branch. The install fails when trying to compile xmppsend:

Cloning into '/root/build/xmppsend'...
remote: Enumerating objects: 75, done.
remote: Counting objects: 100% (75/75), done.
remote: Compressing objects: 100% (73/73), done.
remote: Total 75 (delta 37), reused 0 (delta 0)
Unpacking objects: 100% (75/75), done.
Switched to a new branch '9401665f40723df779f828d01cc1fa6df28b14c9'
gcc -std=c99 -pedantic -mindirect-branch=thunk -O3 -o xmppsend main.c -lstrophe
gcc: error: unrecognized command line option ‘-mindirect-branch=thunk’; did you mean ‘-findirect-inlining’?
make: *** [Makefile:5: all] Error 1
Unable to build xmppsend
sql                 error	Error in SQL transaction: commit failed
sql                 error	Error in SQL transaction: commit failed
sql                 error	Error in SQL transaction: /usr/lib/prosody/util/sql.lua:163: Error preparing statement handle: no such table: prosody
Error: /usr/lib/prosody/util/sql.lua:163: Error preparing statement handle: no such table: prosody

Compiling xmppsend on my main machine (running OpenSuse) does not show the same error. The Suse machine has GCC 9.2.1 while the freedombone machine has GCC 8.3.0.

I am also unsure if the subsequent SQL error is related to the xmppsend failure.