Description:


Additional info:
* package version(s)
$ ssh -V
OpenSSH_7.1p1, OpenSSL 1.0.2d 9 Jul 2015

$ strace ssh -vvv root@foo:~bar 2>&1 | grep open
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libcrypto.so.1.0.0", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libdl.so.2", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libldns.so.1", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libz.so.1", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libgssapi_krb5.so.2", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libkrb5.so.3", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libk5crypto.so.3", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libcom_err.so.2", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libkrb5support.so.0", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libkeyutils.so.1", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libresolv.so.2", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libpthread.so.0", O_RDONLY|O_CLOEXEC) = 3
open("/dev/null", O_RDWR) = 3
open("/proc/10335/fd", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 3
open("/etc/nsswitch.conf", O_RDONLY|O_CLOEXEC) = 3
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libnss_files.so.2", O_RDONLY|O_CLOEXEC) = 3
open("/etc/passwd", O_RDONLY|O_CLOEXEC) = 3
open("/etc/ssl/openssl.cnf", O_RDONLY) = 3
open("/home/rokp/.ssh/config", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/etc/ssh/ssh_config", O_RDONLY) = 3
open("/etc/services", O_RDONLY|O_CLOEXEC) = 3
open("/dev/urandom", O_RDONLY|O_NOCTTY|O_NONBLOCK) = 3
open("/etc/host.conf", O_RDONLY|O_CLOEXEC) = 3
open("/etc/resolv.conf", O_RDONLY|O_CLOEXEC) = 3
open("/etc/hosts", O_RDONLY|O_CLOEXEC) = 3
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libnss_dns.so.2", O_RDONLY|O_CLOEXEC) = 3
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libnss_myhostname.so.2", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/librt.so.1", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libm.so.6", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/liblzma.so.5", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/liblz4.so.1", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libgcrypt.so.20", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libgpg-error.so.0", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libacl.so.1", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libidn.so.11", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libseccomp.so.2", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libcap.so.2", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libattr.so.1", O_RDONLY|O_CLOEXEC) = 3

* config and/or log files:

$ ssh root@foo:~bar
ssh: Could not resolve hostname foo:~bar: Name or service not known

Steps to reproduce:
When connecting with ssh on another server, ssh is resolving entire connection string, and ignoring ":" as separator.

I guess that is connected with next package:
[2015-10-18 09:10] [ALPM] upgraded libsystemd (226-3 -> 227-1); it's the only recently upgraded candidate used by ssh.