Qt Creator may ask for a password, if automatic login is not configured for the version control system. The Linux utility for this task is usually ssh-askpass, but it does not exist on the Mac.
Here is an alternative, originating from Joseph Mocker:
# An SSH_ASKPASS command for MacOS X, with minor modifications to macos-askpass
# by Joseph Mocker, Sun Microsystems.
# To use this script:
# setenv SSH_ASKPASS "ssh-askpass-mac"
TITLE="Enter SSH Password"
DIALOG="display dialog \"$@\" default answer \"\" with title \"$TITLE\""
DIALOG="$DIALOG with icon 1 with hidden answer"
result=`osascript -e 'tell application "Finder"' -e "activate" -e "$DIALOG" -e 'end tell'`
if [ "$result" = "" ]; then
echo "$result" | sed -e 's/^text returned://' -e 's/, button returned:.*$//'
Save it to /usr/local/bin/ssh-askpass-mac, and let Qt Creator know where to find: Preferences → Version Control → SSH prompt command.