I suspect this is caused by bumping debhelper compat (while often a good
idea, this is intentionally *not* risk-free, which is why it requires
explicit action), but I haven't actually tried fixing it by reverting this.
codesearch finds that message in dwz:
https://sources.debian.org/src/dwz/0.12-3/dwz.c/?hl=1016#L1016
dwz was added to the standard dh sequence in compat 12:
https://sources.debian.org/src/debhelper/12/debhelper.pod/#L860
As it seems to relate to debug information, it might be a good idea to
test whether that works:
# apt-get install libsleef3-dbgsym
$ gdb --args <executable (not script) that uses libsleef3>
(gdb) break <somewhere in the sleef source, in file.c:123 format>
(gdb) run
[wait for "hit Breakpoint", or if it's a program that spends most of its
time in sleef, press Ctrl+C]
(gdb) bt full
[should show source line numbers and parameter values, i.e. like #909379
not #914021]
