The attached e-mail makes notmuch from git HEAD segfault: $ notmuch --version notmuch 0.25.1+161~g1b91884 $ notmuch show --decrypt id:86595dab-d486-536b-fe7a-ae3e1dca1a26@posteo.de Warning: Crypto engine initialization failure (application/pkcs7-signature). Segmentation fault Without the --decrypt I can see the visible text, but I'm unaware on how I can make the elisp code not send this command line option.