Description of problem: Sending email using mutt started to fail after I upgraded a computer to Fedora 42 Beta. Version-Release number of selected component (if applicable): mutt-2.2.14-1.fc42.x86_64 postfix-3.9.1-4.fc42.x86_64 How reproducible: Every time Steps to Reproduce: 1. Create a mail in mutt. 2. Instruct mutt to send the mail, i.e., press 'y'. Actual results: Mutt prints "Error sending message, child exited 127 (Exec error.)." Expected results: Mutt should send the mail. Additional info: Running strings implies mutt expects sendmail at /usr/bin/sendmail: $ strings /usr/bin/mutt | grep sendmail /usr/bin/sendmail -oem -oi sendmail_wait /usr/bin/sendmail [...] However, after the update I found sendmail in /usr/sbin instead. I also noted the following during the update: "/usr/sbin cannot be merged, /usr/sbin/arptables points to /etc/alternatives/arptables" Indeed, running the following allowed mutt to again send mail: $ sudo ln -s /usr/sbin/sendmail /usr/bin I suspect this is related: https://discussion.fedoraproject.org/t/f42-change-proposal-unify-usr-bin-and-usr-sbin-system-wide/99853
A fresh install of mutt on Fedora 41 expects /usr/sbin/sendmail: $ strings /usr/bin/mutt | grep sendmail /usr/sbin/sendmail -oem -oi sendmail_wait /usr/sbin/sendmail [...]
https://src.fedoraproject.org/rpms/mutt/blob/rawhide/f/mutt.spec#_117
Same happens to me with mutt-2.2.14-1.fc42.x86_64. Changing /etc/Muttrc.local is my workaround: # Local configuration for Mutt. +set sendmail="/usr/sbin/sendmail -oem -oi"
Both /usr/bin and /usr/sbin on your system should be the same, you can verify with: # ls -ld /usr/sbin lrwxrwxrwx. 1 root root 3 May 14 07:11 /usr/sbin -> bin (note: beware no trailing '/' ) If everything is correct, it does not matter whether mutt points to /usr/bin/sendmail or /usr/sbin/sendmail # /usr/sbin/sendmail -t </dev/null sendmail: fatal: root(0): No recipient addresses found in message header # /usr/bin/sendmail -t </dev/null sendmail: fatal: root(0): No recipient addresses found in message header so it seems like update of your system hit some issue. IIRC filesystem package should do the conversion of unifying bin and sbin directories, but some conflicting package that has files in both with same name can cause it to fail.
My workaround was to add set sendmail="/usr/sbin/sendmail -oem -oi" in ~/.muttrc For me /usr/sbin and /usr/bin are different (I've done several dnf system-upgrade since 2021): # ls -ld /usr/sbin /usr/bin dr-xr-xr-x. 1 root root 69504 May 24 20:17 /usr/bin dr-xr-xr-x. 1 root root 14112 May 23 16:55 /usr/sbin That said, ls -la /usr/sbin/sendmail lrwxrwxrwx. 1 root root 21 May 23 16:55 /usr/sbin/sendmail -> /etc/alternatives/mta # ls -la /usr/bin/sendmail ls: cannot access '/usr/bin/sendmail': No such file or directory And # alternatives --display mta | grep sendmail link currently points to /usr/sbin/sendmail.postfix /usr/sbin/sendmail.postfix - priority 60 follower mta-sendmail: /usr/lib/sendmail.postfix follower mta-sendmailman: /usr/share/man/man1/sendmail.postfix.1.gz Current `best' version is /usr/sbin/sendmail.postfix. So I think we have a bug lurking in somehere but I think it is not mutt related.