libgcrypt is not properly initialized with non-standard home directory (--homedir
or $GNUPGHOME), causing syslog warning messages.
Caused by 'common/homedir.c' refactor between 2.1.12 and 2.1.13. Specifically
function call 'gcry_md_hash_buffer' on L554.
Reproduce with: gpg-connect-agent --homedir=/dummy updatestartuptty /bye
Downstream report: https://bugs.archlinux.org/task/50409