Hi David and Liliana, Thanks David for the added observations. This does indeed look like an upstream bug, but it also seems to have a context dependence because the Debian bug reports list some packages are affected that cause no problem under Guix (e.g. git-timemachine).
As for Liliana's idea of disabling deferred compilation : shouldn't it be sufficient to have all Emacs Lisp packages in Guix AOT-compiled? There would be nothing left to compile in deferred mode. A quick scan of the relevant page on Emacs Wiki (https://www.emacswiki.org/emacs/GccEmacs) suggests that some package manager do this. Cheers, Konrad.
