sudo apt-get upgrade 不是升级包
hp@hp-HP-15-Notebook-PC:~$ sudo apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages have been kept back:
libnss3 openjdk-7-jdk openjdk-7-jre openjdk-7-jre-headless thunderbird
thunderbird-gnome-support
0 upgraded, 0 newly installed, 0 to remove and 6 not upgraded.
hp@hp-HP-15-Notebook-PC:~$
我正在尝试下载 graphics.h 头文件，但之后
1.sudo apt-get install build-essential我的电脑没有升级
2.下载libgraph-1.0.2.tar.gz文件。3../configure它不工作，但错误如下：
configure: error: *** SDL version 1.2.0 not found!
请帮忙？