srcpac fails when upgrading if there is nothing to update:

$ srcpac -Su
error: no targets specified
usage: pacman {-S --sync} [options] [package]
options:
-c, --clean remove old packages from cache directory (use -cc for all)
-d, --nodeps skip dependency checks
-f, --force force install, overwrite conflicting files
-g, --groups view all members of a package group
-i, --info view package information
-l, --list list all packages belonging to the specified repository
-p, --print-uris print out download URIs for each package to be installed
-s, --search search remote repositories for matching regexps
-u, --sysupgrade upgrade all packages that are out of date
-w, --downloadonly download packages but do not install/upgrade anything
-y, --refresh download fresh package databases from the server
--ignore <pkg> ignore a package upgrade (can be used more than once)
--config <path> set an alternate configuration file
--noconfirm do not ask for any confirmation
--noprogressbar do not show a progress bar when downloading files
-v, --verbose be verbose
-r, --root <path> set an alternate installation root
-b, --dbpath <path> set an alternate database location