After upgrading to guile 2.0.12-1 -> 2.0.13-1 the following message shows up:
$this->bbcode_second_pass_code('', 'ldconfig: /usr/lib/libguile-2.0.so.22.8.1-gdb.scm is not an ELF file - it has the wrong magic bytes at the start.')
Downgrading to the old version makes the error go away. This concerns arm6 (Raspberry Pi B+), but might be generic. Who knows what's going on?