The command in question discovered in earlier 7.9p1 and also in latest 8.1p1: ssh-keygen -f "~/.ssh/known_hosts" -R "johndoe" Expected output: known_hosts: No such file or directory The actual result output is: mkstemp: No such file or directory `strace -f` shows: openat(AT_FDCWD, "~/.ssh/known_hosts.TgA5TDcI46", O_RDWR|O_CREAT|O_EXCL, 0600) = -1 ENOENT (No such file or directory) write(2, "mkstemp: No such file or directo"..., 36mkstemp: No such file or directory Please notice the temporary file being created at "~/.ssh/known_hosts.TgA5TDcI46"? Looks like a tilde expansion failure (or lack thereof). ssh-keygen(8) has this to say about the specification of `known_hosts_file`: (*nothing*) I've searched the unix-dev mailing list, patch history, bugzilla (keywords: mktemp, tilde) Introduction of breakage appears to be here: commit 3e088aaf236ef35beeef3c9be93fd53700df5861 Author: djm@openbsd.org <djm@openbsd.org> Date: Fri Jun 1 03:51:34 2018 +0000 upstream: return correct exit code when searching for and hashing known_hosts entries in a single operation (ssh-keygen -HF hostname); bz2772 Report and fix from Anton Kremenetsky OpenBSD-Commit-ID: ac10ca13eb9bb0bc50fcd42ad11c56c317437b58
Actually, I expected this tilde expansion command to work on `known_hosts` file. Expected output: # Host johndoe found: line 1 /home/jilldoe/.ssh/known_hosts updated. Original contents retained as /home/jilldoe/.ssh/known_hosts.old
Tilde expansion is a function of the shell, and you told your shell not to do it by quoting your argument. Compare (this is bash): $ echo ~/.ssh/known_hosts /home/dtucker/.ssh/known_hosts $ echo "~/.ssh/known_hosts" ~/.ssh/known_hosts "~" is a valid path component on most if not all Unix filesystems.
Agreed. It would have worked if the quoted is narrowed down to like any of the following: ssh-keygen -f ~/../../"My Users"/johndoe/.ssh/known_hosts ssh-keygen -f ~/../johndoe/.ssh/"known hosts" ssh-keygen -f ~/../"Johnny Be Right"/.ssh/known_hosts And certainly not the following: ssh-keygen -f "~"/.ssh/known_hosts Got it. I think I'd be asking for an enhancement to the error message, something like including the filename in question that mktemp failed at. If this is not a worthy goal, then let's close this bug.
The error message from the current version seems reasonably descriptive although I'm not sure when it changed: $ ./ssh-keygen -f "~/.ssh/known_hosts" -R foo Cannot stat ~/.ssh/known_hosts: No such file or directory I don't think there's anything else to be done here. Thanks for the report.
closing resolved bugs as of 8.6p1 release