Comment 6 for bug 249526

Same thing here on Alpha-5

Selected Russian from the first screen, walked through all the screens.

On the final screen, where it shows all the details before you click "Start Installation", there's an info string at the top: "Language: No localization"

It seems, Ubiquity switched to the C locale somewhere after selecting the ru_RU locale, judging by this log entries:

Sep 8 02:19:54 ubuntu ubiquity[5603]: Ubiquity 1.9.10
Sep 8 02:19:55 ubuntu ubiquity[5603]: log-output -t ubiquity laptop-detect
Sep 8 02:19:56 ubuntu ubiquity[5603]: log-output -t ubiquity fontconfig-voodoo --auto --force --quiet
Sep 8 02:19:59 ubuntu ubiquity[5603]: switched to page stepLanguage
Sep 8 02:20:00 ubuntu ubiquity[5603]: switched to page stepLanguage
Sep 8 02:20:04 ubuntu localechooser: info: Language = 'ru'
Sep 8 02:20:04 ubuntu localechooser: info: line=ru;2;RU;UTF-8;ru_RU.UTF-8;;console-setup
Sep 8 02:20:04 ubuntu localechooser: info: Set debian-installer/language = 'ru'
Sep 8 02:20:04 ubuntu localechooser: info: Set debian-installer/locale = 'ru_RU.UTF-8'
Sep 8 02:20:04 ubuntu localechooser: info: Set debian-installer/fallbacklocale = 'ru_RU.UTF-8'
Sep 8 02:20:04 ubuntu localechooser: info: Default country = 'RU'
Sep 8 02:20:04 ubuntu localechooser: info: Set debian-installer/consoledisplay = 'console-setup'
Sep 8 02:20:04 ubuntu localechooser: info: Set debconf/language = 'ru'
Sep 8 02:20:04 ubuntu localechooser: info: Set debian-installer/country = 'DZ'
Sep 8 02:20:04 ubuntu localechooser: info: Falling back to locale 'ru_RU.UTF-8'
Sep 8 02:20:04 ubuntu localechooser: info: Set debian-installer/locale = 'ru_RU.UTF-8'
Sep 8 02:20:05 ubuntu ubiquity[5603]: log-output -t ubiquity fontconfig-voodoo --auto --force --quiet
Sep 8 02:20:06 ubuntu ubiquity[5603]: Step_before = stepLanguage
Sep 8 02:20:09 ubuntu ubiquity[5603]: switched to page stepLocation
Sep 8 02:20:16 ubuntu localechooser: info: Locale has been preseeded to ru_RU.UTF-8
Sep 8 02:20:16 ubuntu localechooser: info: Set localechooser/languagelist = 'ru'
Sep 8 02:20:16 ubuntu localechooser: info: Set debian-installer/country = 'RU'
Sep 8 02:20:16 ubuntu localechooser: info: Set debian-installer/locale = 'ru_RU.UTF-8'
Sep 8 02:20:16 ubuntu localechooser: info: Language = 'C'
Sep 8 02:20:16 ubuntu localechooser: info: line=C;0;;;C;en;
Sep 8 02:20:16 ubuntu localechooser: info: Set debian-installer/language = 'en'
Sep 8 02:20:16 ubuntu localechooser: info: Set debian-installer/locale = 'C'
Sep 8 02:20:16 ubuntu localechooser: info: Set debian-installer/fallbacklocale = 'C'
Sep 8 02:20:16 ubuntu localechooser: info: Set debian-installer/consoledisplay = ''
Sep 8 02:20:16 ubuntu localechooser: info: Set debconf/language = 'en'
Sep 8 02:20:16 ubuntu localechooser: info: Set debian-installer/country = 'DZ'
Sep 8 02:20:16 ubuntu localechooser: info: Set debian-installer/locale = 'C'
Sep 8 02:20:16 ubuntu ubiquity[5603]: Step_before = stepLocation
Sep 8 02:20:18 ubuntu ubiquity[5603]: log-output -t ubiquity setxkbmap -model pc105 -layout us,ru -variant , -option grp:alt_shift_toggle
Sep 8 02:20:18 ubuntu ubiquity[5603]: switched to page stepKeyboardConf