我想将 nvidia 驱动程序从 435 降级到 430 或 418，因为 435（和 440）似乎无法与 uswsusp 一起使用以挂起到磁盘和内存。我做了：
sudo apt purge 'nvidia.*'
sudo add-apt-repository ppa:graphics-drivers/ppa
sudo apt update
sudo apt install nvidia-driver-430
但它似乎不起作用：
root@is241395:~# apt install nvidia-driver-430
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
gir1.2-geocodeglib-1.0 gir1.2-gst-plugins-base-1.0 gir1.2-gudev-1.0 gir1.2-udisks-2.0 grilo-plugins-0.3-base gstreamer1.0-gtk3 guile-2.2-libs
libboost-date-time1.67.0 libboost-filesystem1.67.0 libboost-iostreams1.67.0 libboost-locale1.67.0 libcdr-0.1-1 libclucene-contribs1v5 libclucene-core1v5
libcmis-0.5-5v5 libcolamd2 libcurl4 libdazzle-1.0-0 libe-book-0.1-1 libeot0 libepubgen-0.1-1 libetonyek-0.1-1 libevent-2.1-6 libfreerdp-client2-2 libfreerdp2-2
libgc1c2 libgom-1.0-0 …使用 Kubuntu 14.04，我在语言环境方面遇到了一些麻烦。KDE 中的“某些东西”会覆盖我的设置（我在 KDE 中说是因为如果我使用 gnome，我不会遇到任何问题）。
这是我的设置
$ cat /etc/default/locale
LANG="en_US.UTF-8"
LANGUAGE="en"
LC_NUMERIC="fr_FR.UTF-8"
LC_TIME="fr_FR.UTF-8"
LC_MONETARY="fr_FR.UTF-8"
LC_PAPER="fr_FR.UTF-8"
LC_IDENTIFICATION="fr_FR.UTF-8"
LC_NAME="fr_FR.UTF-8"
LC_ADDRESS="fr_FR.UTF-8"
LC_TELEPHONE="fr_FR.UTF-8"
LC_MEASUREMENT="fr_FR.UTF-8"
$ cat /etc/environment
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"
但我得到了（问题是“en_FR.UTF-8”）：
$ locale
locale: Cannot set LC_ALL to default locale: No such file or directory
LANG=en_US.UTF-8
LANGUAGE=en
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC=en_FR.UTF-8
LC_TIME=en_FR.UTF-8
LC_COLLATE="en_US.UTF-8"
LC_MONETARY=en_FR.UTF-8
LC_MESSAGES="en_US.UTF-8"
LC_PAPER=en_FR.UTF-8
LC_NAME=en_FR.UTF-8
LC_ADDRESS=en_FR.UTF-8
LC_TELEPHONE=en_FR.UTF-8
LC_MEASUREMENT=en_FR.UTF-8
LC_IDENTIFICATION=en_FR.UTF-8
LC_ALL=
你对那个怎么想的？
谢谢！